Making Your Own Climbing Holds




Introduction: Making Your Own Climbing Holds

About: I am a software engineer with a background in bridge engineering. In 2012 I bought myself a table saw and started to get in to woodworking which now takes up quite a bit of my spare time. I like to make anyt...

I recently had an idea to build an outdoor bouldering/traversing wall for my children so looked in to the materials I would need to buy. Having looked at commercial climbing holds I was wondering how I might make some myself and if I could make a cost saving. I did quite a bit of research on the net and found quite a few different ways all with a variety of cost and quality associated with them. In the end I decided I would go down the route of making the best I could even though I think in the end I won't save much money at all.....I will have my own one-off custom climbing holds though.

The method I use is to shape a hold in florist foam (oasis foam) and to cast a negative in RTV silicone; this silicone is very flexible and strong, albeit expensive, and cures in around 12-18 hours. I then cast my holds using polyurethane resin; a two part liquid system which I believe is the same as/similar to the material commercial holds are made of. This resin turns out really strong and non-brittle so has less chance of breaking when tightening against a wall or climbed on.

Florist foam - I used a brand called Oasis. I tried the dry and wet foam and found the wet green foam gives a better texture
RTV silicone (room temperature vulcanizing silicone) - comes in two parts silicone + catalist
Polyurethane resin - comes in a two part liquid
Paper clip - optional i used it for stamping in to my hold
M10 bolt and washer - used for reference and making a hole through the hold
I got all of my materials apart from the paper clip from ebay and should be available all over the globe.

10mm drill bit
Cone nose pliers
Glue gun
Thick card
Plastic mixing cups

Step 1: Creating the Hold Shape

I am no experienced climber (only been once about 8-10 years ago) so have no idea about the way holds are shaped and what sizes they might be. I just looked through images on google to get a rough idea of size and shape and just gave it a go.
All you need to do it cut a piece of the florist foam off your big block a little bigger than you want your final hold and roughly carve to the shape you want using a small knife. As you will find this foam is very delicate which makes it ideal for smoothing and final shaping with your can get a little messy though.

Next you will need to create a hole through your hold big enough for your bolt. I use an 8mm auger bit to create my hole is it was something I already had, i then enlarged the hole with my 10mm fixing bolt. I then countersink a larger hole for my washer using a small grinding wheel on my hobby drill. Try to make the hole as perpendicular to the flat back edge as possible as this will reduce the chance of the hold spinning.

Step 2: Making Your Hold Truly Yours (optional)

After a night in making several foam holds with my friend we though it would be good to add some kind of moniker to our holds.
Having come up with several ideas that night and dismissing several ideas the next day I remembered an instructable I had seen about making jewelry out of paper clips and other common items. If you haven't seen the work of Mrballeng I suggest you have a look this guy is amazing, here's a link to give you an excellent guide to bending paper clips!

So anyway i straightened the paper clip and using cone nose pliers to make nice even curves I bent the moniker I wanted and pressed it in to my hold. I do need to look at a good way of doing this as some of the intricacy is lost when pressing on a curved surface. Maybe I'll try gluing it on to a curved piece of wood and kind of roll the impression on? The impression was much more subtle and sharp when I tried it on a flat piece of foam as there was little movement and the depth was uniform.

I thought it looked pretty good though.

Step 3: Making the Mould

Now you have your holds you need to create a negative of it. I did this using RTV silicone but I have see others use 100% silicone from the local DIY/hardware store or clay. I used a glue gun to mount the hold on to some off cuts of laminate flooring i had (any non/low porous flat material will be fine) and the created the edges of the form by gluing strips of thick card I had from some drinks packaging - just make sure you have sealed all the edges properly so the silicone doesn't run out of the sides.
In order to work out the volume of silicone required you can pour in some lentils as they are nice and small and will get in to most of the gaps. Pour the lentils from the forms in to a mixing cup, a cardboard or plastic cup is good, and note the height of the lentils. Next put the cup of some scales pour the silicone in to your empty cup up to the required height. You can now calculate how much of the catalyst you need. Stir the catalyst and silicone together really well until the colour is uniform and you are ready to pour. There are quite a few clips on the internet about the best way to pour silicone which seems to be fairly slowly, from quite a height and in a thin constant stream; this will get rid of most of the bubbles. All you have to do now is wait for approx 12-24 hrs. Once cured break the mould from the form and clean out the inside of  your mould. As you can see from one of the photos I did get a couple of leaks so I sealed them with plasticine which seemed to stop them well enough.

Step 4: Pouring Your Hold and Admiring Your Work

Now that all the preparation has been done you now have a mould that can be used time and time its time to make the first hold. I am using polyurethane (PU) I ordered from the internet, you use it by mixing it at a 1:1 weight ratio. I also ordered some PU dye to colour my holds as I tried using a couple of different things before which didn't quite work. My first attempt was using my kids paint, the stuff with a consistency of PVA, this caused the PU to bubble quite a bit during the curing process making the hold weak and curved on the back (it turns out moisture and PU aren't too compatable). After that I tried some food colouring but couldn't get it to mix as well as I wanted and the hold came out with a pocket of colouring, turning in to a small hole in the front - not structurally bad just aesthetically.
I used a similar method with the lentils to measure the volume of PU required. I weighed the amount of lentils I needed to fill the hold and divided by two, I then poured this halved amount in to a small plastic shot glass; this hold used almost two whole shot glasses. I then put my paper cup on the weighing scales and poured in two shot glasses of the hardener part of the PU and noted down the weight. I mixed in my colouring making sure it was well mixed and then poured in the same weight of the second part PU. Mix this very thoroughly and pour in to you mould. All you have to do then is sit back and relax for half an hour to an hour until it is set.

Once you have waited as long as you can stand make sure the PU is set quite hard by squeezing the mould gently and if it is set turn it out and see how it came out. The first one or two may have some residue of the floral foam on the finished holds but that will soon go. I also got some 2mm thick rubber that came in an A3 size sheet that I cut to the same size as the hold and mount on the back of the hold, which should reduce the amount of spin that may occur when climbing. I haven't worked out how to stick it to the back, super glue didn't work well at all, gorrilla glue was OK, it held it on fairly well but was easy to peel off - I guess this doesn't matter though as it will be between the hold and the wall.

All I need to do next is make a load more climbing holds......oh and I guess I would need to build my wall too, but that will be a whole new instructable!



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    37 Discussions

    I read the comments on here and the thing about cement is that climbers use chalk which when used on the hands to dry them forms into a very thin layer of goo/paste (not sure how to describe it) so my thought is that after climbing on the cement hold a few times, it would be really slick. (Would be a cool/intresting look)

    2 replies

    Also cement doesnt have the tensile strength you are looking for. Cement is great for compression but unless you go the more expencive anchor cement it will likely crack.

    I was thinking about the cement and by pouring salt into the mold before pouring the cement. You could soak the hold in water to get rid of the salt creating the needed texture. I'm guessing this would create a need for more cleaning. (I forget exactly, but my gym used water and some sort of chemical)

    For those interested in doing this, a tip: Do not use wet floral foam! Wet floral foam is open cell and designed to absorb water (to keep real flowers damp). It also absorbs the rtv silicone and you will be left with a mess and an unusable hold. I trust that the author did in fact use both and that his combination worked for some reason. Mine did not :-)

    1 reply

    Hey, I'm not sure which type of foam I did use, it was in 2012, but looking at the photos I used both green and grey foam. A quick image search suggests that green is wet and grey is dry. I didn't have a problem with any foam I used....maybe I was just lucky? Thanks for the tip anyway so others don't get tripped up by the problem!

    100% PU is expensive and the sharpness goes quickly. A sand:PU ratio is harder and less expensive. 25%-50% can be achieved depending on quality of resin.

    Awesome instructable! I would suggest going to a climbing gym and see the holds they use.

    petachock (author) says:
    ...The stresses you would be exerting on holds firstly while tightening then to the wall (enough to stop any spinning)...

    The spinning aspect bothers me. Your single fastening point is below center on some of the designs which would promote spinning.
    5 replies

    "Your single fastening point is below center on some of the designs which would promote spinning."

    True..... Wood holds spin the most (I know that wood isn't in the instructable) When making a hold that is large, If a point on that hold is the obvious point to use for gripping, the further from the bolt the higher the chance that a person is going to cause the hold to spin.

    many commercially available hold have the bolt hole AND a small offset screw hole molded into them so that the hold doesnt spin. It would be an easy addition to this project.

    Most commercial holds have 1 bolt or 2-4 screws as fastening. The holds with screws are not usually purchased commercially (at gyms) because they are prone to cracking and can't usually be reused (I spent years working/route setting at a climbing gym also 2 years climbing in a league which allowed me to go to many other gyms) Holds with a single bolt usually have a washer built into the hold to allow pressure to be applied to a larger area of the hold to prevent cracking/breaking. Screws are a mistake if you plan on reusing the hold. (This was years ago but that is the difference with bolted and screwed holds)

    spinning only really happens if you are using the holds in a specific way. and plus you can always just chuck in a screw or nail to stop it spinning. Other than that just do them up TIGHT!

    I have thought of that and have not built my wall yet and used them in anger so I guess time will tell. I have looked at quite a few professional holds and the bolt holes are often well below the centre. I am adding a thin sheet of rubber to the back and hoping that friction will stop them spinning. If not I will probably drill a small hole off-centre for a small screw to stop them spinning.

    hi! those holds are really nice but i have some questions: is the texture good on the hold and is the object resistent? i saw the resin has a shore D of 65 while generally the resin of the great industries of climb holds has a shore of 75...Does it affect the consistency of the hold? Thank you for helping!

    2 replies

    hi thanks for your comment. The texture on these holds are pretty good, the floral foam gives them a roughish texture to aid grip. Not sure

    not sure how they compare to professional ones though as I am not a climber! Also not sure about the resistance, they certainly seem to be anyway, I guess only time will tell.

    Hi thanks
    Please see my reply to natman in the comments below for info on the PU resin!

    Love it!
    I like climbing but not getting too many sessions this days, maybe i'll make my own wall too.. :)

    Some choose to mold a washer with the holds (like 1st pic on this i'ble for example:, they say it helps prevent cracks when you tighten the holds on the wall with too much force..

    And about the spinning: some glue thin rubber or sandpaper for friction, but you might also want to try making a texturized silicon sheet mold.
    All you need to do is put the sheet over the PU right after pouring into the mold, it should be as easy to peel off when the PU is dry..


    thats awesome!!! could you tell us what ebay stores you bought the chemicals from? and approximately how long/ how much is it to make one of these holds?

    1 reply

    Hi, I first got a small amount of the polyurethane from MB-fibreglass ebay store. Just got a larger amount straight from there web store - I am in the UK by the way so not sure if this will help you. If you search ebay for polyurethane there are a couple of suppliers. The most recent stuff I got is called Polycraft EasyFlo 60.
    To form the holds takes about 10 mins, the time is in making the silicone moulds, I took about an hour for the 4 in the instructable to mount, create the form and pour. I then left these overnight to cure. The polyurethane takes about 30 minutes to cure really hard so they won't break while taking then out of the mould. You may be able to demould after about 10mins though.
    Cost wise the large yellow hold was about 80ml volume and I bought 2litres for £30, some some smaller ones are only about 30ml so you can get an approx price there depending on what you require. The silicone I got was also £30 and depending on the size of hold I think I will get 10ish from that, obviously these can be reused for many holds so the more you make the cheaper overall they are,