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Discussion Starter #1
I've made a number of small fiberglass items after making a mold for them. As you all know the finish of a fiberglass piece dos'nt have to be perfect after coming out of the mold...you can sand/finish it before paint. But CF has to be slick because there is no body work or paint to cover the imperfections.
I've used about any kind of paint on the FG molds before applying the mold release. Just wondering if the CF pieces can be done the same way..or is there a different finish/paint for doing a mold for CF ? I don't see why there would be a difference.
I have my mold done and thought I may need to ask about this before finding out the hard way.:(
 

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When you say applying paint, I assume you are talking about gel coat? And when you say mold release AFTER PAINT, I hope you mean before you apply the gel coat. Is this correct?
 

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Discussion Starter #3
The few small FG pieces I have made I didn't use gel coat...although I do know that is the correct way to make parts. I have just painted the inside of my mold..waxed it (mold release) and made the part. It does come out an ugly fiberglass color instead of whatever gel coat you should use. I guess the only reason I have painted the inside of the mold is to have a better finish to wax (mold release) because there has always been little places that need "body work" on the inside of my (so called molds).
I know this sounds very crude to a person who knows the correct "professional" way of making parts like yourself, but poor people have poor ways lol.
 

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So you're painting the mold first, then applying mold release to the dry paint? Is that correct?

And then laying up fiberglass over top of the mold release?

So, if I'm not mistaken, you're popping a part out that looks like fiberglass and has an amber hue like the resin? And then, after you pull the part out, you chip the paint out of the mold?

Sorry for all of the questions, I've just never heard of anyone doing it like this. Seems like the paint is an extra and unnecessary step if I'm understanding things correctly. If you use a gel coat instead of paint, and use the mold release BEFORE the gel coat, you may end up with a part that has a slightly rougher finish than your method, but it is also very sand able and gives a barrier between the glass and whatever you use for final paint and body. The reason why gel coat is important to use with fiberglass is that it creates a barrier between the glass and finish paint. I imagine that the way you are doing your piece, it probably doesn't take long before the glass starts ghosting through the paint? Correct?
 

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Oh, and what are you painting it with? Gel coat is only about $40-$50/gallon. I can't see any paint being less expensive than that.
 

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Discussion Starter #6
Lol, I'm showing my ignorance now....but I don't mind.. I'm use to it. I've done very little of this and probably have ALWAYS done it wrong...but I've always had to learn on my own and that's the reason for being so far off the "right" way to do it.
I'll make (what I call) a FG mold on the piece I'm making, using a number of layers of cloth and resin. I'll glass in some small pieces of foam or strips of wood to stiffen the mold. I'll then separate the (so called mold) from the actual piece. On the inside there is "unfortunately" always small places/ tiny air pockets to fix...or left unfixed and do work on the piece after being made.This is why I have always painted the inside of the mold, maybe a step that isn't really needed because the paint dos'nt have anything to do with the part being made. These so called molds are always a "one time " thing and I'm sure something you would laugh at.
 

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I'm sure I wouldn't laugh. I'm 100% self taught also and have been doing this stuff for less than 3 years. So I'm not that far removed from making bad molds. In fact, the improvements I've made in my mold making technique over just the past year have been pretty significant.

If it works for you, then it works for you. Keep doing what you're doing and just refine your technique to be just a bit better each and every time.
 

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Discussion Starter #8
Well I sure wish that I had learned more about it years ago. If our "working lives" were measured in months of a year...mine is around late Dec. lol, I'm wore out and about through. I should just stick with frames and cages and leave part making up to people like yourself. But every once in awhile there is a piece that no one makes that I want and attempt to make. This will be the first CF piece for me to make..although I have repaired quite a few CF pieces.
It sounds like it dos'nt matter what the finish is in the mold as long as it is smooth..and waxed good.
 

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Sounds like for your situation, a minor improvement in your mold making would be to get yourself some tooling clay. It cheap and easy to work with. And a damp paper towel helps smooth it off tremendously. That could be a good filler for you on your molds where you have the blown out small air voids instead of using paint to fill them.

And make sure you get the tooling clay from a fiberglass supply store. The stuff they sell at hobby shops is not true tooling clay.

Also, make sure you don't wax the clay and touch your mold afterward. Clay is a wax eraser....lol.
 

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Discussion Starter #10
I've heard of the clay being used but didn't know actually what it was for. I really appreciate your time and words of wisdom on this matter. I'll see how much of that high dollar resin and cloth I can waste now.
Again, thank you for your time.
 

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I've heard of the clay being used but didn't know actually what it was for. I really appreciate your time and words of wisdom on this matter. I'll see how much of that high dollar resin and cloth I can waste now.
Again, thank you for your time.
You're welcome.
 
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