I finally had an opportunity to finish my repair started in February and wanted to post some pictures. I had several hiccups along the way, despite trying learn as much as possible in advance.
In the last photo I had removed all loose material. I then filled it in with the thickened G/Flex:
Applying the three concentric patches went mostly well, except that I tried to pull the painter’s tape after the epoxy had pretty much cured, maybe 12-15 hours. As I mentioned in another thread, it either just ripped, or worse, pulled off a whole sheet of resin soaked resin!
Some places I unfortunately sanded somewhat into the fabric. How do you get smooth edges from concentric layers of fabric? What sanding tool and method? I clearly oversanded.
Here a photo from right after the application of the resin. I’ve learned my lesson and am waiting about an hour for the G/Flex to gel before I pull the painter’s tape and apply the peel ply:
In the water. Note the terrible color match which will remind me of that rock that I hit on the Rio Grande. One day they’ll make Krylon in the right shade of red:
I think your repair looks quite good, especially considering what you started with. It should be stronger than the original material.
The more work you do with cloth and resin, the more little tricks you figure out. I usually let the epoxy cure at least to a fairly stout green state, if not cure completely, before removing the perimeter masking, I use a sharp knife (in my case a surgical scalpel) to incise right along the edge of the masking tape, cutting through any fibers and resin that have overlapped the tape before I try to remove it. I then peel the tape up starting at the side of the tape opposite the repair and lifting it up until it is at a right angle to the hull surface. It is then easy to see and cut through any resin or fibers I may have missed.
I never remove masking tape before applying peel ply. I put the peel ply on as soon as I have finished wetting out the fabric, then use a plastic squeege to force any excess resin off the patch and onto the masking tape. I remove the peelply after the epoxy has cured to green, or fully cured if it is treated, then remove the masking tape in the manner described above.
If you are applying a mulit-layer patch and start with the biggest patch first and progress to incrementally concentrically smaller ones, I have found that with care it is possible to feather the edges of the smaller patches that lie over the larger ones without cutting through the fibers of the larger patches. I do this before I apply a final coat of epoxy to fully will the weave of the cloth. I often use one of those flexible foam 3M sanding blocks with the wet or dry sandpaper wrapped around it instead of a rigid sanding block.
@pblanc said:
I never remove masking tape before applying peel ply. I put the peel ply on as soon as I have finished wetting out the fabric, then use a plastic squeege to force any excess resin off the patch and onto the masking tape. I remove the peelply after the epoxy has cured to green, or fully cured if it is treated, then remove the masking tape in the manner described above.
That’s the method I used for the 3 concentric patches. I was just never able to use the right amount of force with the cutting knife, or maybe it wasn’t sharp enough? I either used too little force and couldn’t cut through or else would use too much force and leave scratches in the canoe or underlying patch. I also couldn’t replicate the rounded edges of the patches and ended up with straight lines and corners. You must be good with the scalpel!
Before I did the two skid plates, I reread Mike McCrea’s post and saw that he pulled the masking tape with the epoxy gelled (I did it after 1-1.5 hours), then applied the peel ply and pushed down the gelled epoxy at the edges, nicely feathering them that way. I tried that method for the skid plates and must say I prefer it. For concentric patches, I think it would minimize or eliminate the sanding since you feather the edges using the gelled epoxy that you push down with the peel ply. It will slightly distort your sharp resin line.
On one of the skid plates, I did have trouble with pleads in the peel ply at the point of most curvature. I was unable to get them out even after repeated tries. I then tried sanding them smooth later, but stopped once I saw some fabric.
