Originally Posted by sblack
I have to disagree that wax should not be buffed. If I recall the mould release wax instructions are to buff it out and I always do. Pva can be tricky to apply on top of buffed wax. I spray a mist coat and let it flash, then I can build it up with no fish eye.
Works for me. For years I used the same old can of Turtle Wax, and it worked better unbuffed. When it ran out I switched to real mold release wax, and indeed, it works great using several buffed coats.
BTW, the green Fiber Glast brand PVA sprays on buffed Meguiars without fisheye:
Originally Posted by C5Engineer
I'm working on making a bubble to clean up my cowling...I was wondering if you had any recommendations on the best way to do a nice cover over the big hole in my cowl. The kicker is the cowling splits right down the middle left to right with fastners so the bubble needs to be removable or...... open to ideas/designs.
Sometimes, when all you need is a blister, the easy thing is to find an ordinary kitchen bowl with the right size and dish shape. Wax the inside, spray some PVA, lay up four plies of 8 harness satin. Pop it out when cured and trim to fit your cowl.
After trim, I'd attached it to the assembled cowl with a flox filet and a few filet plies, then cut the split line after cure. Clean up the edges, wax and PVA one side, sand the other side rough, re-asssemble the cowl, and lay up a flange using some two inch tape. Same basic flange process here:
Originally Posted by Yen
Even laying the weave at 45 deg to sharp corners I still have a less than perfect lay down. I have used an external form at times to get a corner down tight.
Whatever works! I've seen nice external "clamp" forms made from cast rubber. Try Reynolds Advanced Materials.
I vacuum bag layups over complex forms, like this one for composite VW cooling baffles, as good 'ole atmospheric pressure will push the layup down into the concave places pretty well:
Yes, this approach should work for an ECI cylinder. The trick is making the mold form. The actual baffle parts are four plies of 8.9 8-harness, with HTR-212 resin, a room-temp cure epoxy with a fairly high heat distortion temperature:
In any case, I'm not real worried about temperature, as these will have a gasket strip of silicone-impregnated glass cloth between them and the cooling fin tips.