For us newcomers that doesn't have all the equipment in the world.
How do you go about sealing a fairly complicated 3D printed plug, to make a mold for resin infusion.
I am looking to use the uni-mold system but I don't have the equipment to use a spray gun and 2k primer to seal the 3D printed mold
Would it be possible to sand out the print lines of the plug and go up to something like 800-1200 grit and then do the final polish on gelcoat of the finished mold?
But how do I go about not having the plastic plug sticking to the mold?
Is easy lease enough? Maybe some wax and PVA? Will some kind do release tape work (complex shape though)? Seal the plug in epoxy? What about printing in dissolvable plastics HIPS + D-limonene, PVA and water? Print in PLA heat up finished mold in water bath or oven to 60-70C and peel the PLA from the mold? Or just say f*** it and sand the plastic down?

Have a look at a Preval sprayer system. Excellent solution for spray painting smaller objects. Even if you do decide to skip the 2k paint, you will get a much better result if you spray PVA release agent and wont have to do as much work on the mould.

There are other options that will work, like sanding the plastic smooth and spraying PVA, then refinishing the mould. Or Smooth-On 3D-XTC works ok, but isnt perfect.

Certainly if you want a professional standard part, the best way is to have a professional standard pattern - and that means painting it with 2k paints.

2k paints are definitely the way to go if you use a paint system.  Don't be tempted to use simple rattle can paints.  They are heavily laden with solvents which tend to cause issues with the release agents meaning the paint rips off onto your mould and/or the whole thing sticks to the mould.


Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

Thanks a lot for the reply Hanaldo and Warren!!
Sorry for late response
What are you guys opinion on envelop baging, vs regular flange baging, vs silicone bag. to make anything from 20-100 parts in the same mold. and what release agent would you use for that kind of numbers.
Is it possible to make a silicone bag on a existing mold made from the unimold system if I ever get tired of the baging process down the road?
And what would be your weapon on choice to cut a lot of carbon cloth for infusion? needs to be exact up to +- 1 cm. Thin plywood template and pizza wheel? scissors? or something else fancier?

Release agents you want to be using a modern semi-permanent release agent. That will give you a better release every time.

Bagging process is down to whichever you find easier and quicker for your mould.  Flange bagging and envelope bagging both can work well.  Silicone bagging is down to having the right bag shape, suitable seals and ensuring longevity to make it worth while.  Traditional bag and gum tape is technically easier to get  right.

Cutting cloth use a good quality template then some battery electric shears if you want to cut relatively quickly.  Bosch and plenty of other companies offer good quality shears.


Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant