Cowl & ABS plastic repair
Posted November 23, 2010 - 08:44 AM
First, this cowl was in rough, but savable shape. There was a chunk missing on the top lip and the typical cracking damage at the bolt holes. Someone had also drilled a hole in the side maybe for a switch.
Using a really shot cowl, I cut out a patch for the missing chunk (seen above) and that was welded in using a process of a hot air welder and the ABS rod. It's kinda like a tig welder where the hot air welder melts the plastic (looks like a soldering iron) and you melt in the rod. (white stuff in the photo) I had also made a patch using a section of the bolt hole that was better than mine.
This kind of repair is far from "pretty" seeing as hot you are melting plastic almost to a "burn stage" and melting a plastic rod into it. Then it's pressed flat with what looks like a large soldering iron with a flat tip. It does hold as good as anything can hold though.
Next I will show some photos when I sand down the repairs a bit and start the cosmetic rebuild with a plastic repair epoxy.
Posted November 23, 2010 - 08:50 AM
Posted November 23, 2010 - 09:01 AM
Posted November 23, 2010 - 09:56 AM
Posted November 23, 2010 - 10:20 AM
Posted November 23, 2010 - 12:12 PM
Posted November 23, 2010 - 02:43 PM
Thanks guys... Done right it's pretty strong, maybe not as strong as before it broke, but they say it should be. I am not sure I believe it 100% though. I am planning to attach some extra metal to the dash tower so that the entire cowl is supported by metal, not the two corners per side like it is from the factory. I am also going to make an insert plate that fits just over the bottom lip on the inside. That will be made of metal and epoxied to the inside of the cowl and will have the bolt holes drilled in it. I hope this will help keep it from breaking.
One other thing to try is to use fiberglass on the inside.I've bought the kits that come with the resin/cloth/hardner and put a couple layers on the inside.It strengthens everything up nice and its drillable/paintable etc;.Just thougth I'd add this in here.Larry
Posted November 23, 2010 - 03:16 PM
Posted November 23, 2010 - 03:37 PM
It could, but the bond from 'glass to ABS plastic is not that good. I do think that a "patch mold" that was made to fit inside the cowl, and bolted to the lower bolts, as well as the two lower bolts for the metal dash would work rather well. The extra bolts on the top would make it a mechanical "brace" and not a glued on patch. "IF" this was something that people would want, a molded brace.... there is somebody that might build them if the need was there.
Yeah I should have added that about the bond it's not that great but like you mentioned above it's kinda like having a mold inside what you already have an if it's all bolted on together its actually quite strong. I've repaired some of my stuff this way but always looking for better ways.Larry
Posted December 12, 2010 - 10:05 PM
The side to side "stitches" are where the guy tacked them by just melting the plastic. This kept the patch in place while he melted in the ABS plastic filler rod.
Then the bottom side damage was sanded down and ready for filler. I think I am going to make a metal plate the same shape as the inside bottom lip. Once cut to fit and the holes are drilled, I will lay a bed of the repair material all over the inside of the lip and clamp this metal plate to the inside. This will greatly strengthen the cowl and with all luck, solve the problem of it ever breaking again. Once the filler is smoothed and the edges hidden, the paint should make for a modification that really can't be seen easily.
Posted December 12, 2010 - 10:16 PM
You know so many of those plastic dash's a busted up, I haven't seen one yet that wasn't cracked. When I did my 66 I thought it would be a good idea to make one out of fiberglass, about 3/8" or more thick, make something strong like the aluminum ones are, if somebody could do that they would sell.
Posted December 12, 2010 - 10:48 PM
Posted January 26, 2011 - 05:46 PM
Posted January 26, 2011 - 08:02 PM
- Texas Deere and Horse said thank you