loading

Update 03/07/2015: I found the right solution - check the last step!

How did it all start you might wonder, so I will let you know ;)

You might have seen my Instructable for the Simple Induction Heater and with my first one I felt the need to find ways of improving the output power.

The elctronically minded people will already know that ferrite is widely used for small tansformers, choke coils and even antennas.

With this wide variety is is only obvious that you will find a lot of differnt types of ferrite designed for a specific job.

Factors like megnetic flux, core saturation and frequency range are just some of the parameters that can be important for proper performance.

What I use for my needs might not even be considered to be ferrite by a proffesional but it does the job quite good.

This Instructable is a work in progress for me as I will update and complete it with pictures "on the go", so every time I make a new batch or try a new recipe you will see the results here - so keep posted for updates.

If my time permits it I will make the next ferrite during the coming weekend.

It will be plaster based and I shall take some pics and a short video as well.

Please post your comments or improvements and I will update the Instructable accordingly.

Step 1: What Is Ferrite?

Ferrite in the commercial sense is a compressed mix of mainly Iron Oxide and binders.

Depending on the necessary properties, Zink Oxide and even rare earth metals are added.

Usually produced under extreme pressures and heat resulting in a ceramic like finnish.

You can look up on Wikipedia for more detailed info as it is not that relevant for this Instructable.

Step 2: Why Can't I Find Anything to Mould My Own Ferrite?

Quite simple:

There are only a handful manufactorers that have mouldable or machinable ferrite in their catalogue - and they treat their formulas very good!

Also the prices are not really attractive for individuals like you and me.

Even if find a supplier you have to state the purpose and megnetic properties you need or do your own calculations based on the supplied data sheets.

Step 3: Ok, But What Are the Uses of My Homemade Ferrite?

As said in the beginning, I needed something for my induction heater that does not saturate with the extreme magnetic fields involved and also wanted some form of shielding to prevent interference.

With the current mix (at the end of the steps) I accomplished both.

I can't recommend it for the use of specific HF coils or similar as I have no means of checking the properties and magnetic fields with my limited equippment - sorry for that!

But if you make your own electro magnets, induction coils or have the need to generally direct magnetic field lines it might be just what you need.

Also for general shielding of HF frquencies it should work quite well, making it possible to fully seal a circuit in the ferrite so no leaks can happen (or better: should happen).

For example:

A 8mm bolt in my coil with ferrite mantle takes about 90 seconds to get red hot, with a ferrite mantle around the work coil the time is reduced to under 30 seconds.

Step 4: Pro's and Con's

Well, as with all new things they never really perfect ;)

I will start with the negative things first:

* It is very messy to produce, so gloves and outside mixing is highly recomended as you don't want to clean up Iron Oxide dust in your kitchen.

* It is not easy to mix as the Iron Oxide is very fine and tends to ignore all binding at the start of mixing it.

* The mix is not perfect yet, so you might have to test the mix in a small batch to check if it fits your needs.

Now the good bits:

* You can put it into any shape you need.
* It can be sanded or drilled when cured.
* It is a good shield against interference.
* Once mixed it ieasy to handle and form.
* You need no special equippment or expensive ingredients.

* You can easily change the mix to adjust it to your needs.

Step 5: How Is Is Made and What Do I Need?

Tools and things you must have:
* Rubber gloves

* A suitable mixing container - I use the ones to mix plaster

* Spoon, spatula or similar for the mixing

* An area that you clean with a pressure cleaner or that does not mid to get a bit dirty

Things to make it easier:

* Some patience ;)

Ingredients:

* Iron Oxide - the blck kind also know as Fe3O4, commonly used to color concrete and quite cheap

* Plaster - Plaster of Paris, wall filler, or some type of resin depending on your needs (this is the binder)

* Water if you use plaster or similar, otherwise check the instruction for your resin

* Zink Oxide and other things you find when searching for Ferrite compositions if you feel the need and get it cheap - totally optional!

How to mix it:

First some explanations;

You want to use as less binder as possible, otherwise the properties of your ferrite might not be as expected.

For high power applications, like an induction coil, you will need a thick layer of ferrite as otherwise the core will saturate or might heat up - it does not harm to use it too thick and you can always add more (around) if saturation is an issue, same for too much as you can sand t down or use a file.

Only mix as much as you can handle within the curing time!

Take a rough estimation of how much in final volume you need for your project and add another 20% be on the save side.
I go for the plaster version as this was my first way of doing it and because it the easiest.

Add the Iron Oxide in your mixing container (put gloves on now if you forgot about them ;) ) followed by about a third in volume of plaster.
Mix well while dry - for bigger batches using a jar with lid saves you a lot of black dust flying around!

Now add the water and keep mixing like you would for mormal plaster so there are no lumps.

Don't worry if you used too much water as you can always add oxide and plaster.

Be aware that this mix dries a bit faster and can produce cracks in thicker layers, so working in small stages with new mixes to build up might be necessary (keep the dry mix and only use with water what you need).

You now can put it into a mould or cover what you need to shield.

Let it set in a moist enviroment to prevent cracks - I simply wrap it in a moist towel (very old one because of the black oxide!).

After about 2 hours you can continue to let it dry in the open.

Final curing time depends on the thickness and humidity!

To for moisture warm it up to about 30° celsius and place into a closed container that was in your freezer to cool down.
If not fully dry you will see a lost of mist condesing on the inside of your container.

Step 6: How to Use It on Moisture Sensitve Stuff or for Sealing in Electronics

There is only one way and this by making sure the moisture won't get to it!

Either seal it first by means of paint, resin and so on, or make a mould for the ferrite and place the part in it once fully cured.

If that is not an option you have to use a castable or mouldable resin instead of the plaster.

For 2K compositions this means you have to add equal amount of Oxide to both components of the mix.

Although Fe3O4 is not that reactive it can affect the curing of 2K resins, so do a small batch for testing first to make sure it cures properly and does not heat up too much during curing.

It is very hard to give proper mixing ratios as the properties of the various resins differ too much but I work my way down from a 50/50 mix until I notice either mixing becomes a problem or the curing is not good enough.

But usually I don't go under mix of 35% resin to 65% of Oxide.

Step 7: How Can You Help?

You can help to perfect the way of making ferrite by posting your feedback and tested recipies.

I will add more pictures with my next batch and add another step for collected mixtures from feedback for an easy reference for everyone here.

Step 8: Update!

I realised by the amounts of hits that I need to rush things a bit to get this instructable complete.
After experimenting with additives to reduce the risk of cracks forming during the drying process I decided to use this variation for a video on how to make the ferrite.

To give you a head start on the new recipe I will sum it up here so you get a clue what happens in the video.

1. Prepare yourself with gloves and everything you need, you will see the things in the video.

2. Don't try to follow the video straight away, watch it at least twice and make use of the pause button if I am too fast in the video.

3. Don't do it inside as the black dust goes everywhere!

4. Ingredients are:

Plaster of paris - or any other modelling plaster you have at hand (Gypsum).

Black Iron Oxide

A bit of wall paper glue or if not available in your area use wood glue - this helps to keep the mix workable for longer and slows down the drying process also the finnished product does not crack as easy.

Water and some tools for the mixing and modelling - whatever works best for you and the amount you make.

5. The glue should be added to the water first and only in small amounts for wall paper glue, wood glue should be added in a volume of about 15% to the water.

I might skip this bit in the video and prepare the water glue mix upfront as it takes a while with wall paper glue.

Make a dry mix of plaster and oxide, I do this with a spoon.

Depending on the mix you will get a pretty good or preety bad result in terms of mechanical stability.

I try to use 3-5 parts of plaster to 4 parts of Oxide, a 50-50 mix seems to work well but I always try to stay under it to have more ferrite than plaster in the mix.

The more oxide you add the better are the magnetic properties of the finnished product but the harder it is to work with and to cure it without cracks.

Add water (already prepared with glue) followed by your dry mix into a suitable mixing container and mix well until there are o lumps, keep the mix thick enough to work with but not so thin it runs off, unless you do a casting.

Once you start mixing the clock is ticking as you only have limited time until the mix goes hard and becomes unusable.

It is best to work with small batches that you can properly apply before the initial drying starts.

Important!! :

You must use clean tools and containers as even small amounts of cured mix will mess up your next batch!

It will cause the mix to go hard much faster and can cause lumps in the mix when it cures faster than the rest.

I try to wash my tools and containers before the plaster goes fully hard.

As you can see in the video I only make a small amount to get the first layer onto the coil.

I do it this way to allow for a better drying as we want to prevent to capture too much moisture before adding the next layer.

You should take your time to let it dry - either naturally or by the use of a de-hydrator.

If there is too much moisture left before you do the final curing in the oven it result in massive cracks.

Best way is to let the finnished product dry out for a few days before putting it into the oven.

If you cover moisture sensitve parts it is best to add a layer of paint as a barrier, for best results give the paint a quick sanding to get a rough surface as this will help the mix to stick.

In case you are in a hurry try the flexible tile adhesive mixes from your hardware store without the glue in the mix.

But do some small scale tests first to check if your mix produces cracks while drying.


Update 03/07/2015:
I experimented a bit more with a lot of different (possible) binders.
Nothing we would find at the local hardware store, the kitchen or local pharmacy (at reasonable prices) worked.
But then it hit me!
Grabbed my last few spoons of black oxide and mixed it with Sodium Silicate - Waterglass.
Of course, me being me, I did not take any pics or videos - shoot me...
Anyway I will try to explain:
Sodium Silicate is another "forgotten" chemical in terms of home use.
Some might still know it from the chemical experiment "Chemical Garden".
In the concentrated liquid form it is somewhere between full cream milk and warm honey in the consistency and glass clear.
Once dried it it goes rock hard - a feature used for repairs on wood, china ware and other things like heat resistant tiles.
If you know "Green Sand Casting" you are already familiar with just adding a tiny bit of water to that mix.
I did the same with the black oxide.
Started with a few tablespoons oxide and added the Sodium Silicate in tiny amounts.
Creates a lot of lumps and small balls, so doing this in a little ball mill might be a good idea (apart from the clean up bit).
Anyway, if you check the videos on grenn sand casting you will see the mix looks almost dry but keeps it shape when pressed - I tried the same but in the end just used a block form and small hammer to compact it.
(This reminds me to mention to get the ferrite mix out of the form after this step - I did not and it was impossible to remove the cured stuff from the form).
After this the testpiece went into the oven for about 90 minutes at full heat - this creates a nice and hard "ferrite".
To get is hard enough to be actually used it is placed into a kiln and is slowly heated to a glowing orange.
After that the cooling was done in the oven, preheated to full.
Oven was turned off once the piece was in and allowed to fully cool down over night.
The result was that
1. I was unable to get the cured ferrite out of the metal box I used.
2. It is so hard that I could not drill into it.
3. It does not break or crack.

I will try to find some more time and black oxide and make a short video of the process.
In the meantime, everyone still following can experiment as the only thing that matters is to just get the oxide moist with the Sodium Silicate so it binds together properly.
During the compacting a bit of excess might be pressed out indicating to use even less sodium silicate for the next mix.
The only downside is that you have to make a small furnace, metal melter or kiln so you can fully harden the mix, which is basically like a ceramic once cured.

<p>I believe if I just fill a thin plastic tube with iron oxide I will have a nice core, without needing to use any resin, won&acute;t I? Do you see any problem with that?</p>
<p>If things would be that easy...<br>Problem is density and with the oxide it really needs to be as fine as possible.<br>You might get away for some time if you add a tiny bit of water with gum arabic as a binder and compacting it really hard.<br>Main problem is movement once a strong magnetic field is applied, that is why proper cores are usually like ceramic.</p>
Makes a lot of sense...didn&acute;t think about the movement of the particles...:)
<p>hi there, nice post!. im thinking of a toroidal choke (like 10 cm radius x 3cm depth) to use it with my welder ( plan to add rectifier) as lc circuit. I was thinking about polystyrene and acetone liquid (method 4), would u guys have any advice would it be better to use plaster?? thanks in advance </p>
<p>Nice timing, I am in the need of something big in a few weeks too.<br>Unless your welder is an inverter type it might be the easiest to use the core from an old microwave transformer as the choke.<br>Works only for the primary though dow the wire sizes.<br>As for plaster I am only happy with it for high frequency use and where big coils are involved.<br>Simple reason: You need too much plaster to get really high gains in inductivity plus it only works for materials that won't react with water.<br>Iron dust for example will rust before curing unless you have the extreme expensive micro encapsuled stuff.<br>Polysterene and acetone works quite good but is hard to fully cure in a timely way and without too much deforemation on bigger cores.<br><br>Here is how I currently handle bigger things that require half decent qualities:<br>Fine iron powder is moisturised to slightly rust - you want to mix and air frequently until you get enven rust build up without the product turning into rust.<br>Now all is treated with phosphoric acid to convert the red iron oxide into the black oxide type.<br>This will act as an insulator is important to get right.<br>If you have too much iron with no rust you won't be too happy!<br>A quick wash and even quicker hot air dry is required for the next step and should be done before the acid dries on the product.<br>Mix now about 25% by volume with black iron oxide, the finer the powder the better.<br>As the iron powder is quite heavy you are best off using a ball mill without balls for the mixing.<br>Now for the hard part:<br>Prepare some fibreglass resin by adding MEK or Acetone so the resin is less thick.<br>It should flow like warm honey and you should be able to see a drop on a flat surface to grow in size and become flat.<br>I prefer MEK (PVC pipe primer) over acetone as I can smell it better to confirm the core is fully cured - plus it is the base product to make the primer for the resin.<br>Your mixed powder should now be wetted with some MEK, just enough to make clump like green sand for casting.<br>If you can form it and breaks almost clean it is good.<br>Be quick now as the stuff evaporates fast!<br>Add the powder mix into a suitable container, icecreame boxes or jogurt tubs work great as the resin won't bind with it (easy cleanup once cured).<br>Add the activator to your resin.<br>For this you want to use the recommended amount for the volume you had before thinning it plus about 20% extra.<br>Mix the powder and resin as good as you can - what you mess up here will mess with you later!<br>You want to add resin until the mix is plyable without looking dry or creating puddles of resin on the top.<br>Think of it like green sand that you want to make a mould with.<br>When you tap it to compress a slight amount of resin should be coming out to have it perfect.<br>For abovious reasons you casting form should be a bit higher than required ;)<br>Put the mix into the form until filled about half way.<br>Tap and compress the mix to drive the resin out then add more to fill it up.<br>Compress again until you feel the bottom building up.<br>I found the thick end of chopsticks work great for this.<br>Your form should be about 10% higher than what you need and be filled right up.<br>This allows to scrape the resin off so that when done compressing you only have the mix in the form without an additional layer of just resin.<br>Once the leftover resin is rock hard it is time to sand the top off and if you want to cover the finnished product with some acrylic paint.<br>Make sure to warm up so you can check if the MEK is really gone - if you can still smell it leave a few more days to fully evaporate otherwise your paint will never cure ;)<br>Only problem with this method is stability.<br>The iron oxide fills the voids between the iron particles and the resin only the gaps left over.<br>Having some dry oxide in the mix will certainly turn bad here as the resin won't bind to it.<br>If you have access to a 3D printer you can create the mold from ABS which you seal ABS juice.<br>That way the stuff binds very well to the mold and you get added insulation and strength.<br>Feel free to also print a ring to cover the top once fully cured.</p>
<p>Not really too much time at the moment due to work commitments but I thought I post some info on stuff I tested recently.<br><br>1. Flexible ferrite...<br>In some cases it is simply not feasable to create ceramics as it involves temps too high for a normal oven.<br>There are other options I wil mention further down though....<br>From my experience a pure iron oxide ferrite here will be too weak for most applications.<br>For example an increase from 1.4mH with an air core to just 2.2mH with a flexible iron oxide core simple does not justify the work.<br>An even mix of black ironoxide, NiZn (Nickel-Zink) and MnZn (Manganese-Zink) gives far better results.<br>Binder is mostly silicone caulk (50% by volume of the overall mix) and gum arabic (dissolved in water to give 2% by volume) - the rest is ferrite powders.<br>Of course you want them as fine as possible - ball mill comes to mind here...<br>To get the silicone liquid enough for proper mixing I added an equal amount of Methyl Ethyl Ketone and used a spoon to squish and mix until there were no more lumps.<br>Lighter fluid seems to work too but MEK is available for cheap in the plumbng section as the primer for PVC glue.<br>Once done here add the powder(s) and mix properly until you have an even mix.<br>If you want faster setting times then now add one or two teaspoons of corn starch to the prepared gum arabic and water mix.<br>Fill your form and let rest for a few days so all can cure properly.<br>The result is still quite weak in comparision to real ferrite but good enough for shielding (as a paing when still liquid) or for some experiments with magnetic fields.<br>Works great to &quot;freeze&quot; magnetic field lines into some rubbery fun project too.</p><p>2. &quot;Cold sintered&quot; ferrite...<br>I needed a way to least keep my ferrite together until I had it all installed in the bobbins or coil enclosures.<br>But anything clay related or even ceramic meant high temp ovens and press forms - too much for now.<br>So how do you get the small particles to bind?<br>Except for iron powder Sodium Silicate worked quite well for me.<br>Downside is still that you need to create a from and use some pressure to get the excess water content out but at least it does not involve tons of pressure like for sintering.<br>Key is to create an over-saturated solution of the silicate.<br>This means while the water is close to boiling point you disslove silicate until nothing dissolves any further.<br>You can check if it is enough by taking the heat off, with the cooling of the water crystals will form on the surface.<br>Re-heat to dissolve them as otherwise you have problems with the next step.<br>Get a second, heat proof pot or similar and add the amount of ferrite powder required for your form.<br>Now add just enough of the hot silicate mix to get a quite wet mix but not so much that it all ends up swimming.<br>Fill your form with the mix before it cools down , for bigger forms it pays off to pre-heat the ferrite powder in the oven a bit.<br>Press out the excess water content - for this you need a quite tight fit.<br>Use a compressor to blow off the excess (outside please!!!) or some paper towels.<br>Place form (if possible with the cmapls and all attached) in the oven at 120&deg;C for at least two hours.<br>Let cool in the closed oven.<br>The thing will still be wet on the inside and very fragile, so it pays off to prepare the form with some release agent like silicone grease.<br>Once out of the form heat again for sevearl hours but below 80&deg;C as otherwise the crystals form too fast and the form crumbles apart - if have the time let air dry for 2 weeks or so.<br>You check with a digital scale - note the initial and following weights, once there is no more weight loss it is dry.</p><p>3. The quick and dirty one.<br>If you need something simple like a ferrite rod you can create a suitable paper roll template and fill it with a mix of molten wax and ferrite powder.<br>The mix should be in such a way that when you let it rest for a moment little to no wax should form a puddle on the top.<br>If you still have dry, crumbling lumps you need more wax though.<br>Fill in your paper form and let cool down - make sure to have some cm in additional length as the wax will shrink in the center.<br>Once cooled down cut to the prefered length and remove the excess paper.<br>Be aware that due to the nature of the binder this is nothing for permanent use unless in constand cold enviroments.<br><br>4. Plastic ferrite....<br>I tried glue sticks in the beginning and let me just say it is a huge mess!!!<br>The powders clump and won't really mix properly, the heat control is a nightmare at the best of times and the mess it makes....<br>I needed something easy to make, easy to handle and that is at least strong enough to hold the ferrite together.<br>ABS-juice...<br>If you have a 3D printer you know what I mean, if not: It is ABS plastic dissolved in acetone.<br>Natural, colorless ABS works best as some colors are added as pigments rather than dyes.<br>Use an old jar with a properly fitting lid and you can prepare quite a bit and keep it stored in a cool place.<br>I make my mix so that is almost like honey in consistency.<br>The ferrte poweder should be wetted with acetone prior to adding - this will help preventing lumps and makes the mixing far easier.<br>The working time you have depends on the temperature and wether or not you can close your mix airtight.<br>This is also the downside of this method.<br>Bigger forms can take weeks to fully cure and harden as there is little to no vaopration happening once the outside is hardened.<br>Instead the remiaing acetone works it way out by sweeping through.<br>Like in a cell membrane it will try to equalise and so the entire thing is weak until fully cured.<br>Even if it feel already hard on the outside the inside can be still soft.<br>A good way to check is to put the core into a closed yar and to warm it up to about 40&deg;C for about 2 hours or more if you want.<br>When you open the yar and smell acetone it is not fully cured.<br><br><br>I hope this gives you some more ideas to tinker and discuss here ;)<br>Thanks for following!<br><br></p>
<p>Awesome! As someone who spends a large percentage of their time on electronics projects, I often find I need more ferrite than I can afford. The torroids required for the winding of inductors and transformers are actually very expensive, especially for an individual on a strict budget. This is a great solution, as the materials required are inexpensive and the mix can be molded in ways that you could never find pre-made. </p><p>I have not yet made any of this ferrite, but I do have plans to create a giant homemade flyback transformer (the ones I ripped from two virtually identical televisions sucked). Alas, I have browsed the online stores time and time again, and every single time I look for a giant flyback transformer core nothing pops up. So, I guess my two paragraphs of commenting are really asking if I can use a custom mold to create a giant transformer core. I know I can definitely mold the stuff into the shape I want, but will it work for such a high-voltage application?</p>
<p>The voltage does not really matter as you would isolated wires ;)</p>
I made transformer for spot wedding (150 amps 12 v ) . how can I use it for induction melting
<p>No offence but I think you are in the wrong Ible...<br>Check my Ible about the Induction heater and you will realise that for melting you need a lot of electronics to control the frequency and power.</p>
<p>Hey bud, any updates on this? Did you ever end up getting the sodium silicate to work? Did you try epoxy resin?</p>
<p>I did some more experiments on a small scale but still struggle with the actual removal f the core from the mold.<br>There are two problems the need to be addressed to make it work properly:<br>a) The right consistency.<br>So far I tried from pretty wet to a mix similar to what is used for making green sand.<br>Less is better but too little and it all crumbles.<br>b) The curing.<br>Air drying sodium siicate takes forever and it does not get the hardness required.<br>Only around 300-40&deg; C in my tests it starts to form crystals.<br>Problem here is that the stuff tends to expand massively while doing so.<br><br>I am trying to make a tiny mold from teflon that I can screw together to press a short ferrite rod.<br>Through tiny hole the water s supposed to be able to evaporate during the heat cure.<br>But time is a bit limited here so I can do this when I am free enough and the brain is doing it's job.<br>But it is not forgotten!</p>
<p>Have you considered making your mold(s) using a Vacuum Former with sheet plastic? There are some quite clever DIY Vacuum Former projects out there which utilize your kitchen oven to pre-heat the plastic sheet, and a small household vacuum to form the heated plastic around an appropriately shaped object (torus/rod).</p><p><a href="https://www.instructables.com/id/Make-a-good,-cheap,-upgradeable-sheet-plastic-vacu/" rel="nofollow">https://www.instructables.com/id/Make-a-good,-cheap,-upgradeable-sheet-plastic-vacu/</a></p>
<p>I did some experiments as I have a vacuum pump at hand but so far my main problems are a lack of time due other projects and commitments and right now the lack of use.<br>Have a nice metal case, power supply and water pump sitting here to make a new iduction heater.<br>For this one I also want different work coils includig some at least one pancake coil for sheet metal use.<br>When the time comes to it I think I will make a new Ible for it all and include all the different recipies and their outcomes so far.</p>
<p>Awesome, nice work mate! Have you considered the normal procedures of using a PVA release agent and an a casting epoxy resin? I think I am going to try to make one this weekend, if I manage to get the time. I need a gapped square shape, similar to this, but square.<iframe allowfullscreen="" frameborder="0" height="281" src="//www.youtube.com/embed/axM177JrIBo" width="500"></iframe></p><p>. I am going to try and make a wooden screw down mold, using the epoxy resin and some release agent. It &quot;should&quot; pop right out of the mold after about 10 hours air cure time. It should be ok to be carved and drilled, or even hit it with a dremel if needed. I just had a project with a epoxy base gel resin that worked great. I will let you know how I go.</p>
<p>I tried the resin method qute early on but never liked the results as you have to make the decision between a really sturdy result and something that might crumble apart.<br>It is also quite hard to keep the oxide particles supended without sinking down.<br>But I have to admit I only used cheap fibreglass resin and did not do too many tests after I noticed the core density was very low.<br>Please go ahead and try your way and if you at least semi like the results post them.<br>If they are really good make an Instructable out of it.<br>At least we got the ball rolling now :)</p>
<p>haha thanks mate for you info! top stuff. I got some stuff to give it a crack. I could not find any epoxy that was reasonably priced. I am going to have a crack at your plaster of paris. first....will let you know the results</p>
Very Electro Cool downunder ! it takes your inventory 30 seconds to heat an 8mm bolt holy smokes! I need to make a ferrite insulated induction coil forge , for tool making, Nice write up too man, very easy to read and follow the steps. <br>Collecting hard or gummy tree sap from around your area, is worth while as it sets like glass , keeping tree sap in a jar with a lid and about 4 part water 10part sap ) soaking sap in water Makes the sap soft like silicone and js easy to mold or use as glue , takes 24 hours to harden <br>Keep up the research mate
Tree sap is fire proof and doesn't melt and is freefree
<p>Just as clarification, the pine tree resin (AKA pitch) mentioned above by <em><strong>Downunder35m</strong></em> is definitely <em>NOT</em> fire proof. On the contrary, pine and fir tree resin are commonly collected and used to <em>help</em> start a fire in damp conditions. They will ignite and burn very very energetically.<strong><br></strong></p><p><u><strong>Difference Between Sap and Resin:</strong></u><br>&bull; Sap is really the sugar that is found in the xylem and phloem cells in trees. Resin is a liquid which is stored in the outer cells of trees. <em>(When a tree is cut, resin oozes out and clogs the broken area similar to blood clotting a wound.)</em><br>&bull; Resin is normally red, clear and hard. Sap is yellowish or white, sticky and gummy.<br>&bull; Resin can also be described as a substance which initially has a highly viscous state, but hardens once treated. Sap is actually made of sugar and water.</p><p><a href="http://www.differencebetween.net/science/nature/difference-between-sap-and-resin/" rel="nofollow">http://www.differencebetween.net/science/nature/difference-between-sap-and-resin/</a></p>
<p>Looks like I'm the first commenter. I am wanting to use this material to make Toroids for Joule Thieves and also to wind Rodin Coils. Now Rodin Coils are presently wound on Air Cores but they have a lot of properties not yet discovered and work needs to be done on ferrite toroids. It is just that Toroides of the Size I am talking off become rather expensive. This looks to be a possible alternative to the financial disaster independent research already is. </p>
<p>For project like yours I recommend to experiment with resin instead of plaster or similar as a binder.</p><p>For Joule Thiefs I actually prefer to use ferrite beads as they can be found in old printers and amplifiers.</p><p>An basically every motor inside you will find small ferrite toroids perfect for a Joule Thief, check my Forever Light for some examples.<br>But back to your big size ferrite cores...</p><p>If you get a 50-50 resin it would be perfect for the mix but usually you will only find the stuff (at reasonable costs) that needs only a few drops of hardener/activator.</p><p>In any case you want to add as much black iron oxide as possible, so you need a resin with a quite long curing time - don't go for anything with working time under one hour!!</p><p>I experimented on a small scale with 2K glue and had quite good results, so it might works fine for your smaller projects too.</p><p>Be aware that you won't be able to get same same density as commercial ferrite meterials which and compressed and cured by heat that turn the binder in ceramic.</p><p>So where you would usually use an air gap to prevent core saturation you will most likely see that it is not necessary as the home made ferrite simply can't reach the flux densities.</p><p>Another option for a quick check, especially for rodin coils would be to fill a plastic doughnut just with the Iron oxide powder - far from perfect but would show you if there is a noticable difference in flux and magnetic field properties.</p><p>As a &quot;last resort&quot; option for a very quick mix you can also use tree resin, like from pine trees.</p><p>Collect what you can find and try to get the dry stuff not the honey like goo that is fresh.</p><p>Measure by volume how much ferrite you would need.</p><p>Heat the resin slowly until it melts and add a little amount of powdered charcoal - this makes your binder.</p><p>Add the ferrite slowly making sue you keep enough heat and stir well.</p><p>When you notice you can't bind more ferrite add a bit more resin - as I said you want as little binder as possible.</p><p>Once you got enough use it while it is still hot, once it cools it will be rock hard!</p><p>For this to work properly on a doughnut you will need to make a plaster cast for two halfs - top and bottom.</p><p>Pre-heat the cast and fill with your resin mix, scrape of any excess while still hot.</p><p>Do the same for the other half but leave the excess and press the two parts together while the second cast is still hot - if you can keep both hot to assitst the binding process.</p><p>Once cooled down sand it clean and try it out.</p>
I am actually considering using a device similar to a centrifical extractor to build the toroids and the material will be dried with heat and under centrifical force. This should remove all possibility of cracking. As to the binder I am actually considering Epson Salt as it can be melted at low temperature and will mix readily with the Ferrite oxide. Once hard it is like rock and will conduct electricity as well as the ferrite so there should be no interference with the flow of the created fields.
<p>im interested in if you every tried this epsom salt idea and how well it worked?</p>
<p>Nice idea, please post your results!</p>
<p>To make it harder use fire clay or ceramic clay and fire it.</p>
<p>Tried that and the results are not that good.</p><p>You need too much of the clay to create something that does not crumble when finnished.</p><p>In lame man's terms: If there is more binder than iron oxide the performance of the ferrite will be very poor.<br>Ceramic might work better but I had no chance to test this yet.<br>Did you do any tests with ceramic or was it just an idea?</p>
<p>It would be really nice to see some more pictures of the process....!</p>
<p>They will follow next weekend the latest, right now I am a bit short on time.<br>The process is pretty simple, like making a cake mix but a complete set of pics to explain the process is coming soon!</p>

About This Instructable

33,367views

27favorites

License:

Bio: I like to improve myself and things I find :) Learning new things every day is next to impossible but I still try - only a working ... More »
More by Downunder35m:X96 (S905x) Android TV Box - Updating the Firmware and Costom Roms The Paracord Stubbie Holder My Little Paracord Splicing Guide 
Add instructable to: