I need to make a mold of a product that has to be painted tomorrow so I need to make a quick mold but still good so I can replicate the product perfectly.
Does anybody know any places in IL that sell tooling gel coats? I understand its important to spray the item with a tooling gel coat before you apply fiberglass over it but would it be so bad if I didn't use fiberglass?
Is it safe to just wax it 20 times and go straight to wetting the product with fiberglass? Or do I still need PVC coating?
The product will be sanded and painted after demoed from the mold so if its very minor damaged its ok because I can fix it, but the mold has to be good.
Any input? Any experienced or semi experienced people know anything? Until then IM youtubing it!
I've always heard it called "mold release" that is sprayable or on rare occaisions brush on.
How about some plain old Saran Wrap in a pinch.
How big of a mold are we talkng here ? The bigger the mold the more important it is to use wooden "buck" backers to keep the new mold from warping as the new fiberglass mold cures (warpage - big problem with making new molds).
tooling gel coat is a iso geloat that can hold up better then regular gelcoat, it wont crack with heat and wont shrink like regular and is more scatch resitant. if tou are making a mould that only a few parts ae going to be pulled you can get away with regular gelcoat, some of the marine grade gelcoat is iso. You will ant to wax the part you want to make the mould off, u need to use mould release wax, a good coat first to fill in all the pores let it hardin up and buff clean yoy will need to do this 5 to 7 times each time you buff the wax you will feel the mould starting to get more slick you can never wax enough, once the wax is done you should apply pva mould release a prevail works great first coat haze it on and hen a few light coats once dry you are ready to make your mould, i often apply a coat of wax over the pva and buff lightly for the hard to release shapes.
now you can spray or brush the gel, there are two types of gel brushing which is thick and spray which isthin but you will need a 2 or bigger tip to spray, u an reduce the gel with up to 10% acetone to help spraying, but let the acetone flash for a minute, with spraying gelcoat forget every thing that u know about paint this stuff is totaly different, you will need to put on min 14 mills max 22 mill to little and the gelcoat will wrinkle once you place the resin and mat, to much gel and the gel will start to prerelease .
once the gel is hard you can throw on the glass, the gel will remain a little tack, first have your mat ready cut rip and tear the mat the trick is you dont want any overlaps these overlaps cause hor heat and will distort in time, wet out the gelcoat with resin and drop down the glass with a brush wet out the mat remember that the mat has a binder in it and the resin will break this down in a min or 2 once the matt is wet you need to get rid of all the air that is traped u can use a steel roller what i use is a laminating brush an ut the bristols a inch this ives a very still brush and u can perice the air our the less resin on the matt the easier it is.
after the first coat of glass is dry give is a quik sand with 40 or 60 to remove any spikes also if you see any air bubbles this is the time to cut them out a exacto knike should work, fill in and repair with geloat thicken with talc.
now add 2 layers of mat let dry, and then add another 3 layers, and then another 3 layers, this will give you a 1/4 inch mould, for siffness you should build a ply wood frame and fiberglass it on to the mould, pop the mould off and your good to go, his will give you a low prodution mould, for high produion you will need a thiker mould and higher grade resind like epoxy to mom shrikage
I do R/C planes also and alot of guys make their own molds and they wax them heavily like you said ,20X , but I don't think they used car wax they used some wax just for mold releasing. The mold is highly polished before they apply wax and still sometimes it can be hard to get it to release
just make sure your plug is exactly how you want it without flaws. Use some meguiars wax. you can wax it about 6 times and PVA isn't necessary, it's just insurance but it *should* pop off no problem. 1 day is really rushing it as i dont know what type of part you're making. Is it something that needs to fit perfectly or? You generally want to make your mold 3 times thicker than the part but if it's a 1 off it's not as important. If you lay up all your fabric in 1 session, the amount of exotherm will make your part warp like a potato chip so be careful. it's better to take your time. good luck