precaution when trimming your part ?

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precaution when trimming your part ?

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Jess8bit	Jess8bit posted 12 Years Ago HOT Topic Details
Group: Forum Members Posts: 133, Visits: 566	Hi guys, Do you take any particular precaution when you trim your part with your Dremel ? How do you protect the surface from scratches that may occur during the trimming ? I've had this problem : the srface was nice after demolding. After triiming the part, I've jad the bad surprise of observing many scratches and holes in the surface. My assumption is that I made the scratches myself simply by holding the part with my hand (with gloves on) and handling it durng the process (maybe because of carbone dust ?). Hence the question. I'm thinking about covering the surface with a plastic film hold by masking tape all around the part edges. What do you think ? thank you !!
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carboncactus	carboncactus posted 12 Years Ago HOT Post Details
Group: Forum Members Posts: 243, Visits: 1K	Looking at that last picture....... Take a heat gun to the surface for a couple of minutes. I have taken prepreg parts out of the oven and they looked a bit flakey. Like dry skin, sort of. Applied heat and the epoxy gelled a bit then fully cured, absorbing the dryness. Edited 12 Years Ago by carboncactus
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Matthieu Libeert	Matthieu Libeert posted 12 Years Ago HOT Post Details
Group: Forum Members Posts: 955, Visits: 3.4K	I would go for the same theory as fred... I mostly wait 2 days before sanding epoxy... mostly I even postcure first and let the part cool down again for a few hours before sanding Matthieu Libeert Founder MAT2 Composites X Sports website: www.mat2composites.com
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Jess8bit	Jess8bit posted 12 Years Ago HOT Post Details
Group: Forum Members Posts: 133, Visits: 566	matthieutje65 (05/06/2013) I would go for the same theory as fred... I mostly wait 2 days before sanding epoxy... mostly I even postcure first and let the part cool down again for a few hours before sanding Ok, I will definitely wait longer before demolding and trimming. Maybe 20¨C is a too low temperature to work as fast as I'd like May I ask you how you post cure your infusion-made parts ?
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fgayford	fgayford posted 12 Years Ago HOT Post Details
Group: Forum Members Posts: 433, Visits: 1.2K	carboncactus (05/06/2013) Looking at that last picture....... Take a heat gun to the surface for a couple of minutes. I have taken prepreg parts out of the oven and they looked a bit flakey. Like dry skin, sort of. Applied heat and the epoxy gelled a bit then fully cured, absorbing the dryness. I will second the heat gun attempt. Fred Did you lose vacuum when making this part?
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Jess8bit	Jess8bit posted 12 Years Ago HOT Post Details
Group: Forum Members Posts: 133, Visits: 566	fgayford (14/06/2013) carboncactus (05/06/2013) Looking at that last picture....... Take a heat gun to the surface for a couple of minutes. I have taken prepreg parts out of the oven and they looked a bit flakey. Like dry skin, sort of. Applied heat and the epoxy gelled a bit then fully cured, absorbing the dryness. I will second the heat gun attempt. Fred Did you lose vacuum when making this part? Hi Fred, are you refering to the problem shown on my very last picture, or the former ones ? Also, I can't be sure about losing the vaccum, apparently no, but how to be sure since the bag is clamped at both extremity (vac + feed lines) and there is no gauge on it anymore ? thank you
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carboncactus	carboncactus posted 12 Years Ago HOT Post Details
Group: Forum Members Posts: 243, Visits: 1K	Your vacuum was good, as there is no pinholes. Unless vacuum was lost after gellation Does the gelcoat follow the shape of the part? If it does, then you just had a bridge. Inject it with some more GC50 next time you mix some up. Edited 12 Years Ago by carboncactus
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Jess8bit	Jess8bit posted 12 Years Ago HOT Post Details
Group: Forum Members Posts: 133, Visits: 566	carboncactus (14/06/2013) Your vacuum was good, as there is no pinholes. Unless vacuum was lost after gellation yeah, I'm really starting to consider this might have occured. Hard to know though. Do you think that if I warm up the border with a heat gun, the, the GC would stick to the resin again ? Does the gelcoat follow the shape of the part? If it does, then you just had a bridge. Inject it with some more GC50 next time you mix some up. Yes the GC follow the shape. But don't see how to "inject" it.
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carboncactus	carboncactus posted 12 Years Ago HOT Post Details
Group: Forum Members Posts: 243, Visits: 1K	No the heat gun trick is only for uncured epoxy laminates. Get a smackhead needle on eBay, lay the part down so the void is horizontal, then stab with a pin. When you get the courage, inject some gelcoat into the void. You could also use lacquer or epoxy. Let it overflow a bit and cure. You should have a tiny blob just poking out. Rub it with 1500 and polish. Edited 12 Years Ago by carboncactus
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