Epoxy
This is something I'd never attempted before and it took about 5 minutes for me to realise
that I didn't have the faintest idea as to what I was doing! However, when I was surfing about trying to demystify the enigma that was Epoxy I found the offer of a free User Manual and Product Catalogue. I was a little dubious until it arrived a couple of days later and found that it covered all the basic techniques required to complete the taping and filleting.
With Uncle John being based in America some of his site content is specific to America for example www.RAKA.com who only ship within the USA, its territories and Canada. So I hit the yellow pages and started to look for Epoxy or Resin or anything that would help. I eventually got the number of a chandler on a nearby island and rang them. "Yes we do Epoxy resin kits" they said. Off I trotted and returned an hour later £24.00 lighter with a 1.2Kg pack of West System Epoxy. This would have probably been enough to tape the seams and little more. Two packs would have done the minimum that Uncle John recommends. By the time I finished I'd used 4 kits and could have saved money buying the 5Kg pack and would have still had resin left over for modifications or repair should the need ever arise. The point of this project was to have fun building a boat not learn budgeting. So I fluffed the costing a bit, so did the engineers building the Channel tunnel, and when I build the next one I'll know better.
It originally seemed like a really good idea to start by taping the outer seams first, this way I thought if I mess up the taping no one will see it. Sound logic eh! We'll come back to this "good" idea later. I started by taping the sideboard and stem seams mainly because they were short. This went fairly easily and I felt my confidence increase a little, I'd mixed more resin than I needed but made a note to myself not to waste anymore resin. Plan well ahead of yourself when you do the epoxying. I wasted so much resin to start with and didn't improve much until I bought a small 2½ inch roller and then everything improved greatly. As always use the correct tool for the job and the job is simpler by far. After I'd taped all the outer seams (not including the outer Butt Joint seams) I left it to cure.
The next day I washed off the waxy "bloom" that had formed during the curing process due to temperature and humidity then rubbed it all down with 120 wet and dry paper. I used wet and dry mainly to keep the dust down and make wiping down afterwards a bit quicker. After everything was clean and dust free I slapped another coat of epoxy over the bottom of the boat and all the glassed seams. I eventually ended up coating the entire boat with at least 3 coats of epoxy on all surfaces, some got more due to over coating and paranoia (again).
Now it was time to learn how to fillet. This involved spreading thickened epoxy over a joint and then drawing a rounded filleting tool (a tongue depressor to you and me) along it to leave a smooth cove-shaped fillet bordered on each side by a clear margin. Oh yes? Really? This took some practice to get right, it took me a while to figure out that my resin mix wasn't thick enough either. Ho hum...
Next day... One remix later and double the amount of filler (sawdust from the belt-sander) we were getting somewhere. After this lot set... (move on one more day) I started again.
This time I cut all the tape for the inner seams and rolled them up ready for when they were needed. For this mix I used the West System 406 Colloidal Silica (a general purpose filler and thickener) and found it performed much better and with greater consistency. We fair romped along in this session and I was able to add some extra strips of glass-tape across the floor to increase the strength around the area where I'll be getting in and out and sitting! When I finished it was 1a.m. the following morning. I started working in the evening as it's cooler and the epoxy's liquid or open times are longer. (learning...slowly)
When all the joints were taped it was time to add the end eyes and coat the inside of the Pirogue with epoxy. By this time I had a better idea of what I was doing and coating the inside with 3 coats was completed in one hit.
Coating with epoxy is similar to working with concrete. Pardon? you stutter. It's like this - if you pour wet concrete onto "green" concrete (that is concrete that has set but not cured and has a green colour hence the name) it will chemically bond together forming one piece rather than being physically bonded to the layer below. The same is true with epoxy, if you overcoat a layer of epoxy that hasn't yet cured it forms a primary bond and sets as one thick layer rather than two layers with a secondary or physical bond (achieved by rubbing the dry layer with sand paper to "key" the surface). When the epoxy had cured it looked like this.
By this point I thought that all I had to do was rub the thing down and paint it. How wrong was I? Yes, very wrong. Remember that "good" idea I had earlier, well this is where I found the flaw in my logic. Everything was going well as I rubbed down the insides, no problems. Turned the boat over to do the outside and everything went fine till I rubbed down some of the tape covering the seams. This is where I found that the bubbles of air trapped behind the tape had resulted in a few serious weaknesses as I rubbed the areas down. After I finished poking around I'd opened up a couple of 3 to 4 inch gaps and an assortment of crap bits that needed to be filled.
I thought about patching these bits but opted for the "Sod it, lets just tape the whole lot again" approach. So one more trip to the chandlers for tape and more epoxy. I bought 2 inch glass fibre tape this time as strength wasn't the issue here and I wanted to keep the cost down.
Again I was able to do the whole job in one session and it was much quicker than the original taping of the seams. To start with I mixed a small batch of epoxy and thicken it up with Silica and filled all the holes and gouges I'd created then glassed over the top straight away. As I was adding tape I decided to add a strip over the Butt joint in the bottom (just in case, again. So I am paranoid what of it?)
Painting & Finishing
With Uncle John being based in America some of his site content is specific to America for example www.RAKA.com who only ship within the USA, its territories and Canada. So I hit the yellow pages and started to look for Epoxy or Resin or anything that would help. I eventually got the number of a chandler on a nearby island and rang them. "Yes we do Epoxy resin kits" they said. Off I trotted and returned an hour later £24.00 lighter with a 1.2Kg pack of West System Epoxy. This would have probably been enough to tape the seams and little more. Two packs would have done the minimum that Uncle John recommends. By the time I finished I'd used 4 kits and could have saved money buying the 5Kg pack and would have still had resin left over for modifications or repair should the need ever arise. The point of this project was to have fun building a boat not learn budgeting. So I fluffed the costing a bit, so did the engineers building the Channel tunnel, and when I build the next one I'll know better.
