Recently on http://www.thingiverse.com/ there was a contest called "Make it Float" which made me question whether a 3d printed part will naturally have the capacity to keep water from flowing in through the delicately laid lines that make up the piece. After a little research and checking out some of the different prints submitted to the contest I concluded that indeed a part can be printed in such a way that it repels water and floats.However, parts printed with "standard" settings and with an optimized print time in mind do not commonly have this ability. The plastic naturally floats in any water but it is more like an ice cube than a foam board (floats IN the water not ON the water). This brought to mind an issue which needed solving... how to make any print water proof, even when gaps between lines occur.
Step 1: When Where and Why
The world of 3d printing is expanding at an incredible rate. People are printing houses, cars, bicycles, and boats. With this influx in prototype and production, prints will undergo all sorts of different environments and stresses. The environment that this instructable deals with is liquid, and how it effects your print. I will show a way to apply a coating on your print to prevent liquid from entering your infill, or deteriorate your outside.The coating of choice will be WAX because it is readily available to most people, but there are many other types of coatings that will do the same thing, and possibly do them better.
Coating material is commonplace in most every industry, Carbide tooling is often coated in a TiAlN (Titanium aluminium nitride) to prevent wear while cutting, allen wrenches and socket heads are often coated in a black oxide to prevent rust and wear, and even couches and beds are coated in a flame resistant resin in case of fire. 3d prints currently use coatings for many different reasons also, to smooth edges, to increase toughness, and to block liquids from entering. So WHEN your print is in need of any of these attributes look to coatings for help.
Each 3d printed part is different so discovering WHERE is unique to the instance. A few rules I use are as follows: does my print interact with liquid on a regular basis, if yes then WHERE does it interact, apply the wax to that specific spot. If you are not sure WHERE it interacts, just apply wax everywhere and you will be sure to get it. An example would be a 3d printed boat (like this one from Thingiverse http://www.thingiverse.com/thing:763622 a great print to test the capability of your printer also) most boats only need wax applied to the bottom of them, and a small amount of the lower portion of the sides. Use your discretion as to the best place to apply wax and if all else fails, just put it everywhere!!!
I have already answered this question in the WHEN and WHERE sections but 3s are the best so I will reiterate it here. Wax on a print will prevent water (or other liquids) from breaking into the print because wax creates a water tight barrier. This is WHY you should use wax to coat your objects.
Step 2: Coating a Print
Now that we have covered the basics of WHEN WHERE and WHY lets figure out how to efficiently apply wax to our print.
- 3d Printed Part
- Wax (any kind really, if you want cool colors to match your print try melting down crayons...)
- Brush (both to clean the part and to apply wax)
- Heat Gun (or heat source hot enough to melt wax)
- Container (for heating the wax)
-Knife or Razor
1. CLEAN THE PRINT
2. MELT THE WAX
3. KEEP THE WAX WARM WHILE APPLYING
4. COOL THE WAX
5. REMOVE EXCESS WAX
NOTE: having excess wax is not really a problem, but if your object is supposed to float it will add unnecessary weight to it. Also it will make it look odd if it has an uneven amount of wax applied to it.
NOTE 2: Only a small amount of wax is needed to make the print water tight.
NOTE 3: Putting wax on the print will make it "waxy" so hold on tight and use gloves or it may slip out of your hand/ get your hands "waxy".
CAUTION: Heat Guns can get very hot so use caution if you are using this method to melt your wax. Also keep the heat gun on the wax as you are applying it to make sure it stays melted as it will harden quickly.
Step 3: Checking for Leaks
After you have applied the wax and let it cool, it is time to check for leaks. Use a container of water to dip the part in forcing it to submerge as much as needed (until the wax is underwater) and allow to sit for a set amount of time (10-15 seconds). If water fills the cavity of the print then apply more wax and try again until you do not have any water inside and you are sure the part is water tight!
Step 4: Smoothing Everything Out
Once you have made your object water tight it may still be in need of some "cleanup" so grab your knife or razor and very carefully remove any excess wax from your print and try to clean up any "fingerprints" you may have left from handling your part. Any wax can be used for this process (even crayon wax) and finding a wax that matches the color of your print may be your goal (or maybe not if you want a cool color contrast).
If you liked this Instructable check out my other ones by visiting my page and keep an eye out for more innovative ways to use 3d printing to its maximum capacity!!!
If you live in North America and want something printed, check out my 3dHub at this URL.
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Thanks God Bless