A forum for discussing wooden boats and boat building

You are not logged in.

#1 10 Jan 2017 4:08 pm

AndrewG
Member
Registered: 10 Oct 2016
Posts: 7

Epoxying the inner hull

Just epoxied the inner hull of a Nymph canoe which didn't go too well.  I think that the problem was even though the garage was at about 17 to 20 C, the resin and hardener had not had a chance to heat up so was too viscous to soak through the cloth easily. Even though I got some help doing it, we ran out of time and were not able to get all the runs and voids it before it started to gel.

OK so now it has set is there any way of correcting the voids? These are small circles of about 1cm diameter which are still white where the epoxy has not soaked through the cloth completely. Thought of getting a syringe and injecting the epoxy. Anyone done this?

As for the runs, do you scrape these off before applying a filler coat of epoxy? I think I'll need several coats to cover up all the bumps and uneven patches.

The outer hull epoxying went much better, but really the instructions gloss over the epoxying. I took great care to get everything organized beforehand and get help, but even so am not happy with the finish. I hope it is recoverable!

Offline

#2 11 Jan 2017 4:18 pm

Gudgeon
Member
Registered: 23 Feb 2012
Posts: 13

Re: Epoxying the inner hull

This is a bit outside my experience but I suspect that you can cut the fabric out where it is white and fill the holes with thickened epoxy.  I did soemthing like this when I made a fabric tunnel at the bow of my boat and it seemed to work.
I recommend that you contact Fyne Boats for advice- they are probably too busy at this time of year to monitor the forum too closely.

Offline

#3 12 Jan 2017 9:26 am

Paul
Employee
From: Gatebeck Cumbria
Registered: 4 Aug 2011
Posts: 114

Re: Epoxying the inner hull

Gudgeon is right you can repair this but it will probably mean that you will have to paint the area rather than varnish it.

I suspect that your epoxy was too cold when you applied it to the fabric.  The trick is to get the epoxy components really warm and runny before you mix it and pour it on the fabric.

If the white area is solid and there is no air bubble underneath it you can apply more epoxy over the top.  From what you say I do not think that the fabric will go transparent but remain white: this means it will not be at its strongest but for your purposes it should be strong enough.

If there is a gap or air bubble under the white area, that is you can depress the white patch, you will need to fill this gap.  If the area is small you can probably cut a small hole in the fabric with a Stanley knife and inject epoxy under the fabric using a syringe or just squeeze it in.  If it is a large area it would be easiest to cut the white area out and fill the hole with slightly thickened epoxy.  Unless it is very large I would not patch it with fabric.

Please send some photographs to Fyne Boat Kits and we will give you advice on how to proceed.

Offline

#4 12 Jan 2017 4:32 pm

AndrewG
Member
Registered: 10 Oct 2016
Posts: 7

Re: Epoxying the inner hull

Paul,

Thanks , I'll send in some photos. There is air behind the white patches and you can depress it. If I scrape away with a  Stanley knife blade I can get the white patches out. Was planning just to do a fill coat with epoxy once I've done this.

Andrew

Offline

#5 13 Jan 2017 3:19 pm

Phil
Employee
Registered: 8 Jun 2011
Posts: 52

Re: Epoxying the inner hull

Andrew,

Whatever you do these white patches need removing.  Then you need to sand the wood underneath to key in for more epoxy.  Next you need to patch in some glass fabric set in epoxy which you will feather in once cured.  That done it will look as it should and the wood will be properly protected behind glass fabric.  If the white holes are really small, less than a 10mm, then I would remove the white glass, sand then fill with epoxy

Next step, fill the weave and prepare for varnishing.

I hope this helps.

Phil

Offline

#6 14 Jan 2017 1:47 pm

AndrewG
Member
Registered: 10 Oct 2016
Posts: 7

Re: Epoxying the inner hull

Thanks for the advice. I've cut out as many of the white patches as I can and refilled with 2 coats of epoxy. Looks a bit of a mess, but as it is the inside I may be able to get away with the slight unevenness where I had to cut holes and fill with epoxy.

Still not that happy with the finish. There also seems to be some  lighter patches where one piece of strip joins another, presumably leftover glue (though I sanded away a lot). These are not voids, and are invisible to the naked eye until you epoxy it. Too late now, but would be interested for the next canoe, If I build one, how to avoid these patches. They make it look a bit like old wood that has been varnished.

Offline

Board footer

Powered by FluxBB