Drying filler and mitt question


Chest Nut
I took on the task of filling my canvas canoe project last night. I know to expect about 5 weeks for drying time. Is there any advantage to moving the canoe into the baking sun to help the filler dry?

Is it possible for the filler to cure too fast due to the heat of the sun?

Someone had mentioned glueing their canvas mitt together instead of sewing... what a great idea! My biggest hold up was getting around to sewing my mitt, the glue method worked pretty good.

How many mitts per canoe is normal? I did just the one and it was pretty much filled solid (smooth) by half way through the canoe. It's too late now but what are you after with the mitt? The sandpaper tecture of a new mitt or the smooth surface of a used mitt?

How many coatings of the filler did you put on?...I do the tradional 3 coats..first one rubbed in well, second one with a new mitt, then the third with the latex gloves...second coat should smooth it out and then the last coat with the latex gloves does the final smoother almost glossy look until it sets up and goes dullish!...once it sets, I just write the date on it with a marker, cover it, walk away. Summer and heat didnt effect mine in the past but others may have had some bad experiences in the past and can answer that part. From start to finish, I can usually do a 3 coat fill in about 1-1/2 hours!.by the time you get to one end rubbing you can usually go right back and start another coat....some even have a second person rubbing behind them as they lay it on..when done right it should look like a smooth chalk board!...:) Pictures of your progress are always welcome...We are not a motley lot!....Its called a labor of LOVE!

"Love many,trust few, and always paddle your own canoe."...Native logic!
I don't recommend putting a freshly filled canoe into the baking sun. Let it dry out some first. You don't want it to dry so fast, initially, that it shrinks and cracks. The sun is good to "polish" the cure.

I usually make a new mitt for each canoe, using glue of course! The mitt is a sort of fine leveler. I squeegee out the first coat and rub the second with a mitt, then let it sit for awhile before I rub it out with a latex glove. I tried using my bare hand years ago but have switched to the latex glove so that I can keep my fingerprints. I get the results I like with two coats, and it cures a lot faster.
Having just received a PM asking about the squeegee method, I figured that others may ask as well.

I use the flexible plastic ones that one uses for fiberglass. Usually called autobody filler spreaders, often marketed by Bondo. I have recently tried the yellow plastic ones like you would use for drywall patching, hey work well, too.

As the filler "dries" out quickly when first applied to the canvas, you apply only about 1-2 square feet of area, then spread the filler out and press it into the weave. You have to work it while it still behaves like a paint, not a sludge.

Go around the canoe. When complete, start the second coat, but this time you get to work about 3-4 lineal feet of the canoe. The second application requires a very light and delicate touch with the spreader. Lately, I've started to skip the spreader on the second coat, and just rub it out with the mitt. I think that I tried that only once so far, so my memory is not clear on it.

Once you get all around the canoe, let it set up for about 30 minutes, then go over it with the canvas mitt to level off any small ridges, etc. After about an hour you can polish it with the latex gloved hand. If you try and polish it too soon, it is a little too "mushy".

When I've tried the three coat method, I found that the third coat didn't really make it any smoother than what I was getting using this method, and it took a lot longer to cure. If I were not able to get as smooth with the first coat, then yes, three would be required.
Thanks for the squeegee info Douglas. I was going to try that on the next canoe (next week by the look of the rainy weather report..I have to canvas outside for now). I thought it might work well as that's what worked (for me anyways) on the few cedar strip/epoxy canoes I've made.

My last batch of filler was thicker than I am used to (a new brand of silica might be the culprit and I'm still learning about mixing my own) so I had a real bear working it in. I should have thinned it a little but once I started I didn't want to stop. Was a good work-out and arms were stiff for two days after that...maybe I'm just getting old! A squeegee would have been the ticket. It came out fine in the end, anyways.