How Did You Repair Cowl?
10-23-2006, 09:40 AM
#1
How Did You Repair Cowl?
I have an old fiberglass cowl I need to repair. To complicated to explain why not replace. It has a few extra holes in it; and the cowl retaining screw holes are elonged, etc.
What methods have any of you used to fill holes before repainting. thanks.
What methods have any of you used to fill holes before repainting. thanks.
10-23-2006, 02:15 PM
#2
Join Date: Dec 2001
Location: Upplands Vasby, SWEDEN
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RE: How Did You Repair Cowl?
Hi!
Good quality professional 24 hour Epoxy resin ( Not the hobby stuff epoxy or West, is not that good)...or polyester resin . 50g ordianary Glass-fiber cloth weave and 105g satin weave and brown micro balloons!
That´s it!
Regards!
Jan K
Good quality professional 24 hour Epoxy resin ( Not the hobby stuff epoxy or West, is not that good)...or polyester resin . 50g ordianary Glass-fiber cloth weave and 105g satin weave and brown micro balloons!
That´s it!
Regards!
Jan K
10-23-2006, 03:56 PM
#3
Join Date: Jan 2003
Location: Sarnia, ON, CANADA
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RE: How Did You Repair Cowl?
I think JAKA has the right idea, he just didn't explain it very well.
Start but cleaning the cowl thoroughly with alcohol,
Paint a thin coat of epoxy on the inside of the cowl and then apply a layer of very light fiberglass cloth. Depending on the extent of the repairs several pieces may be required.
Once hardened; use the microballons to fill in the holes from the top side and sand smooth, paint as required.
This is a long process that requires patience, but can strengthen the cowl and completely hide many sins.
Good Luck!
Start but cleaning the cowl thoroughly with alcohol,
Paint a thin coat of epoxy on the inside of the cowl and then apply a layer of very light fiberglass cloth. Depending on the extent of the repairs several pieces may be required.
Once hardened; use the microballons to fill in the holes from the top side and sand smooth, paint as required.
This is a long process that requires patience, but can strengthen the cowl and completely hide many sins
.Good Luck!
10-23-2006, 04:07 PM
#4
Senior Member
RE: How Did You Repair Cowl?
Actually, there are a couple of things worth mentioning.
It's really tough to repair cracks. If you're going to repair them anyway, then go ahead and mess 'em up enough that you can actually get good coverage and penetration. The repairs will then have a chance of strengthening the area. And trying to sand a fill ill fitting cracks is more work than just fixing a larger area.
In a lot of cases, Bondo works worders. You don't want to try and fix large areas with it, but it's great for filling on the outside when the glasscloth underneath is still there. It sands great. It doesn't do what epoxy can do, but it's a bit easier to use for filling places. It's just a tool that's nice to have in your tool kit.
I just worked on a cowl that needed a couple of hold down holes moved, and a big muffler hole filled. The original 4stroke engine was being replaced with a 2stroke and mufflers were way different. The original muffler outlet hole was at the bottom of the cowl and went around to the side as well. I needed to fill a large area and the area had a distinctive shape.
I took some stiff paper. It happened to be the paper that's used for targets for target shooting. It's sorta thick and a bit porous. I eased it into the shape needed and taped it against the outside of the cowl. It was tight enough to the cowl that it sealed the opening, and it replicated the cowl that was missing's shape. I then painted from the inside with epoxy. I used 30 minute Zpoxy from the LHS. Works great. After painting in a coat, I laid in one layer of 2oz glass cloth (also from the LHS). After working it flat and saturated with the brush, I laid another layer of 2oz. I didn't add anymore epoxy, but worked the 2nd layer flat and made sure it was saturated. After making sure there was no puddling or drips, I turned off the lights and came up here. Next morning I pulled the tape and lightly razored the excess target paper away. The inside looked like normal layup. The outside looked messy. I sanded with 320 and all the paper that didn't have epoxy in it dusted right away. There wasn't much effort to block sanding what was left to match the contours of the existing cowl. Some target paper remained in the hole. But from the outside there were no holes around the rim, no pinholes in the "cloth", a good job all around. When the sandpaper had removed what paper it could remove easily, what remained was where I wanted to fill. Some finer sanding and paint and it'll be good to go.
I used epoxy with phenolic filler on the screw holes that'll be moved. Fill them, then drill new holes where they need to be. No sweat.
It's really tough to repair cracks. If you're going to repair them anyway, then go ahead and mess 'em up enough that you can actually get good coverage and penetration. The repairs will then have a chance of strengthening the area. And trying to sand a fill ill fitting cracks is more work than just fixing a larger area.
In a lot of cases, Bondo works worders. You don't want to try and fix large areas with it, but it's great for filling on the outside when the glasscloth underneath is still there. It sands great. It doesn't do what epoxy can do, but it's a bit easier to use for filling places. It's just a tool that's nice to have in your tool kit.
I just worked on a cowl that needed a couple of hold down holes moved, and a big muffler hole filled. The original 4stroke engine was being replaced with a 2stroke and mufflers were way different. The original muffler outlet hole was at the bottom of the cowl and went around to the side as well. I needed to fill a large area and the area had a distinctive shape.
I took some stiff paper. It happened to be the paper that's used for targets for target shooting. It's sorta thick and a bit porous. I eased it into the shape needed and taped it against the outside of the cowl. It was tight enough to the cowl that it sealed the opening, and it replicated the cowl that was missing's shape. I then painted from the inside with epoxy. I used 30 minute Zpoxy from the LHS. Works great. After painting in a coat, I laid in one layer of 2oz glass cloth (also from the LHS). After working it flat and saturated with the brush, I laid another layer of 2oz. I didn't add anymore epoxy, but worked the 2nd layer flat and made sure it was saturated. After making sure there was no puddling or drips, I turned off the lights and came up here. Next morning I pulled the tape and lightly razored the excess target paper away. The inside looked like normal layup. The outside looked messy. I sanded with 320 and all the paper that didn't have epoxy in it dusted right away. There wasn't much effort to block sanding what was left to match the contours of the existing cowl. Some target paper remained in the hole. But from the outside there were no holes around the rim, no pinholes in the "cloth", a good job all around. When the sandpaper had removed what paper it could remove easily, what remained was where I wanted to fill. Some finer sanding and paint and it'll be good to go.
I used epoxy with phenolic filler on the screw holes that'll be moved. Fill them, then drill new holes where they need to be. No sweat.
10-23-2006, 06:19 PM
#5
RE: How Did You Repair Cowl?
Thanks, great tips. I got a Pilot kitted Pitts with an incredible paint job, partly on cowl. the plain yellow part of the cowl has a lot of extra holes, etc. One of these days I want to refurbish the cowl without messing with the custom painted part.
