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A few newbie type questions

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Old 01-28-2008, 04:43 PM
  #101  
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Default RE: A few newbie type questions


ORIGINAL: JKEpps



ORIGINAL: daven

I'm surprised you were able to wax over the PVA without it pealing up?? How did you do that?

Parts look nice
I had success and failure with that. My plan was to apply three coats of wax, but after the second one, or actually during buffing it out, the PVA started to peel a little. I decided to quit while I was ahead. I used a soft terry cloth towel to buff out the wax. I used Mother's Carnauba paste wax, and let it dry for apx 30 min. I wonder if I use the Mequire's liquid Carnauba wax if maybe I could get the three coats before the PVA lifts.

Speaking of PVA. I did have a couple of areas that didn't come out exactly correct because the PVA puddled on the bottom of the mold. I didn't see it at the time. Now I know not to set the mold in a position for the PVA to puddle. Setting it upside down did allow it to dry nice and even.

-Jorden
No kiddin'. You absolutely don't need to wax the PVA. When I make polyester parts, the PVA will stick lightly about half and half to the mold and to the part and can usually be peeled off. When making epoxy parts, the PVA bonds slightly to the epoxy - a little water though and it washes off right away leaving a very shiny surface. I use two coats of wax on the mold (three or four for the first part or two) and then PVA in three coats - first a very light mist coat followed by two solid coats that stop just barely short of laying down a smooth layer of paint. Stop spraying just before the PVA starts to look smooth and leave it just a little orange peeled - it will lay down as it dries. Too much will leave bubbles.
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Old 01-28-2008, 04:56 PM
  #102  
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Default RE: A few newbie type questions


ORIGINAL: TeamSeacats

No kiddin'. You absolutely don't need to wax the PVA. When I make polyester parts, the PVA will stick lightly about half and half to the mold and to the part and can usually be peeled off. When making epoxy parts, the PVA bonds slightly to the epoxy - a little water though and it washes off right away leaving a very shiny surface. I use two coats of wax on the mold (three or four for the first part or two) and then PVA in three coats - first a very light mist coat followed by two solid coats that stop just barely short of laying down a smooth layer of paint. Stop spraying just before the PVA starts to look smooth and leave it just a little orange peeled - it will lay down as it dries. Too much will leave bubbles.
I figured I didn't have too. I'm experimenting. I had read somewhere where the wax on the PVA helped with release, PVA not staining/ruining the layup, and with painting in the mold, which is apparently a problem when trying to paint directly on top of PVA. I'm getting better at applying the PVA. I've used the "paper towel" method, and most recently a sprayer. I've read where using a square cut from an old T-shirt, then dip, apply, wait 1 minute, and polish the PVA with the same cloth works well. I dunno, but worth a try. I think I'll do another layup, and try painting in the mold this time to see what happens. Vacuum bagging is coming up. I don't have an electric pump, but since it's a small part. I figure the hand pump I use to bleed my brakes on the car should work. We'll see.

-Jorden
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Old 01-28-2008, 05:10 PM
  #103  
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Default RE: A few newbie type questions

Everyone seems to have there own method for applying PVA, or not in many cases. Personally, a spray gun works well for me, but it is such a thin fragile layer of protection, I've had it peal just trying to brush epoxy through the glass.
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Old 02-10-2008, 09:55 AM
  #104  
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Default RE: A few newbie type questions

Ok what are micro-ballons, never even heard of them before this.
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Old 02-10-2008, 08:20 PM
  #105  
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Default RE: A few newbie type questions

Microballoons are microscopic glass spheres that you mix into epoxy to create a lightweight, sandable filler. You would mix in enough to make the epoxy as stiff as, say, whipped cream. Folks use them a lot for fillets, etc. If you didn't know what it was, it would look almost like talcum powder to you.

Head up to the TH website and look for their part number LXHZ15 to get an idea of what they are.

I hope that this helps,

Bob
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Old 03-07-2008, 10:46 PM
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Default RE: A few newbie type questions

Dave, did you ever lay-up those Seeker wings? I'm still very interested in the process. Thanks
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