plug and mold making

General Composites Discussions Composites Talk
#1

This is a grueling job to say the least! So many different materials to work with but not every one will do the job specific to what you need. So you have to choose the materials wisely.

The freaking cost of making plugs and molds is expensive, even when labor is not a factor.

I’ve dropped $130 just for supplies to build one small plug and one small mold. I haven’t even bought any gel coat, wax, or pva yet. Can i make my own gelcoat for less $ than it cost to buy ready made? How? Anyone know where i can buy Maquires Miror Glaze mold release wax for a good price?

I still need some 1.5 to 2 ounce plain weave fiberglass cloth… one yard should do the trick. I am using 1.5oz csm and 10oz f/g cloth for the mold, when i get that far along in this process.

In line with this thinking i am going to make a mold that can pop out many parts. It cost more than a plaster of paris mold, but it’s better in my opinion.

If I sell parts i make i’m definately going to have to factor into the price the cost of mold making. Mold making is not easy to do. The lay up is the easy part!

#2

Dude… tell me about it! I’ve spent the better part of $3K since March (various resins, core materials, cloths, and sundry consumables), spent well over 300 hours getting the pattern/plug just right, been through an interesting learning curve on semi-perm releases… and I’m just NOW getting around to building the mold for the hood! Now, I have enough material on hand to get the job done, and THEN some, but still… you’re absolutely right. There’s nothing “all ya gotta do is…” about any of this. But like you said, if you want something done a certain way, the only choice you may have is to do it yourself.

To answer your question on Meguiar’s wax… I got mine from US Composites… about $10. Personally, though (and after having used both), I’m partial to TR-104 HiTemp wax. Seemed eaier to apply and wipe off. Just my $.02 worth.

#3

Any carnuba wax will work but the composites types has a high work temps ranges.

Besides plaster of paris, you can use Hydrocal and Ultracal from US Gypsum and they also have some that you can even machine on them too.

If you use P of P or these others ones, you can add burlap or chopped FG strands into the mix for added strength!

Fiberglass: On eBay

							Item number:  								300128991965[IMG]http://pics.ebaystatic.com/aw/pics/globalAssets/rtCurve.gif[/IMG]
#4

I use the TR as well. It drys faster and is not as greasy to wipe off.

#5

Dual Twill you are the third person i have heard recomend the TR mold release wax. I will give that one a go when the time comes for waxing.

Thanks Werksberg and DT:cool:

#6

I bought a 25lb bag of P of P dry mix. The burlap is an excellent idea as is the chopped fiberglass.

How thick can i get this stuff. i need to make a plug off my bike. It’s a one-off part that won’t be made again as far as i know. Unless someone on the sportbike forums i visit wants one made.

Can i lump on plaster to be about 1 inch thick if i do it in layers allowing dry time between layers? Also if i poke holes into cardboard will P of P stick to the cardboard and stay put? I was thinking the burs from the hole poking would help hold it onto the cardboard long enough. maybe i’ll use bondo body filler?