Filling Technique

[shelldrake]

Good Morning,

I'm planning on filling my OT 50 Lb today with Rollin's stuff. I've been reading the Stelmok/Thurlow books, the instructions that came with the filler and threads posted here. The books describe immediate recoating after the first application and completing a 3 sq ft section with all three coats before moving on to the next section. However, the instructions suggest coating the whole boat with the first application before moving on to the 2nd. Which way is the best?

Also, I have read a few historical posts that indicate problems with loosening of canvas after filling under certain conditions. It is going to be in the low 90s and humid here today. But I will be doing this in inside, out of the sun.
Are these conditions suitable for filling?

I want to do it right the first time, so any thoughts on these questions would be appreciated.

 

[Mark Adams]

I usually do it in 3rds. Roll one coat out, let it "set up" then rub it in. Roll out the 2nd coat, but extend it to the second 3rd of the canoe. The third coat covers the entire boat, and then the process reduces by 3rds. Hopefully that makes sense!

Mark

 

[shelldrake]

Thanks very much Mark. I guess a roller is faster than a brush? I decided to postpone the filling until it cools off and drys up a bit. Humidity is very high today.

Thanks again,

Matt

 

[Paul Miller]

Hi Matt,

I have always put one coat at a time on the whole boat, just working it into section by section.

I also use a roller and rub it after coat 2 &3 with the canvas gloves and finally hand rub/stroke for the final step.

You should have very sore arms by the time your done. I once did a 25' war canoe and hope not to do another anytime soon.

I'd wait for a less humid day to canvas, but I don't think is should be a problem for filling.

Good luck,

Paul

 

[Dave Osborn]

IMHO......High humidity is your enemy when canvasing. Took me three time, but I finally figured out the common denominator on those jobs needing restretching........HUMIDITY! I now run a dehumidifyer in the shop when conditions are "iffy".

 

[shelldrake]

Thanks for the interesting replies Dave and Paul. I am going to wait for the weather to cool down and dry-up before filling.

Regarding stretching canvas and humidity Dave; are you suggesting that if the canvas was stretched during high humidity, loosening and wrinkles may appear later? I'm thinking that if the canvas was stretched when damp (high humidity), it would shrink and tighten up once it dried out? As it turns out, on my stretching day the humidity and temperature where relatively low. So, hopefully canvas loosening will not be in my future.

Thanks again for the replies. As I mentioned earlier, I would like to go through the process (on this boat) only once!

Matt

 

[Dave Osborn]

In my opinion, it seems that canoes swell in high humidity, much as they would if sunk or rained on. I canvased a canoe during unusually high temps and humidity along the shore of Lake Superior, another time under a tarp on a rainy, humid September day here in the Northwoods, and both times I needed to re-stretch the canvas. I don't recall the third occasion, but all had high humidity. When the humidity dropped, the canvas was loose.
For the most part, re-stretching isn't that big of a deal, except when you have to "unbutton" the canvas at the stems, providing you left something to grab ahold of to pull it tight again on the sides. On the ends I used a pair of pliers with a flat nose to grip and pull to re-tack the stems.

I never trim canvas close along the gunwales until all filling and painting is done. The untrimmed canvas protects the gunwales from paint and filler....don't have to mask it Trimming it is the last thing I do prior to installing the outwales.

 

[Mark Adams]

Once you put the filler on it, it pretty much stabilizes the canvas. The oil in the filler kind of "plasticizes" the canvas. Just don't get it soaking wet after. I was wet sanding the topsides of a shellac bottom canoe once, without the shellac on, and man o man were there wrinkles when the raw filled canvas got wet!

Mark

 

[shelldrake]

Well, as I said, I stretched during low humidity and now it's very hot and humid and no looseness has appeared. So, hopefully I'm OK. It will be at least a few days before I will have time to fill, so if any wrinkles appear I can re-tighten before filling.

Should I use a foam roller cover for the filler, or just a regular paint roller?

Thanks again,

Matt

 

[Mark Adams]

I use a regular roller, with a 3/8 nap. I also use one of those shielded rollers as the filler is heavy enough it kind of gets flung all over the place.

Mark

 

[shelldrake]

Good tip Mark.....thanks

Matt

 

[Paul Miller]

I'm getting confused by some of these posts.

So I might think some new comers might get confused.

Canvas does the opposite of most materials. When canvas gets wet or absorbs moisture, it shrinks and gets tighter around the canoe. When it dries out it relaxes.

I don't think anyone said that directly.

Paul

 

[Dave Wermuth]

Also

The wood of the canoe swells/shrinks with moisture. So be cognizant of that ... I think the wood swelling then shrinking is more of a cause for the canvas to get loose. Is that right? the wood moves more than the canvas?

 

[Dave Wermuth]

And yet another random thought

I have stopped burning the nap off. I no longer singe the canvas with a torch. I had an unfortunate experience. I have heard of others doing the same.

 

[Steve Ambrose]

I have stopped burning the nap off. I no longer singe the canvas with a torch. I had an unfortunate experience. I have heard of others doing the same.

Ignited a runner did we?

 

[Paul Miller]

Some of us are old enough to remember camping in a big canvas tent, one with those sidewalls that would fit 8 or 10 sleeping bags.

When you got up in the morning that tent would be tight as a drum from the dew on it. It could even pull the tent pegs out of the ground. By mid-day is would be limp again and you would be pulling those ropes tight with those wood handles that adjusted the lines.

I always varnish the inside of the canoe prior to canvasing and we all put something on the outside before we canvas, so the wood should not be swelling much at all.

The canvas is what gets tight when at a high moisture content and relaxes when very dry. I think someone already mentioned that the canvas once filled can not absorb very much moisture and hence doses not move much.

I always fill the canvas right after I put it on. I never wait for another day.

Paul

 

[shelldrake]

OK, now I understand the theory........I canvased when it was relatively dry three days ago. It is very hot and humid now. The canvas is tight. Should I go ahead and fill, or wait for the humidity to lower to make sure the canvas does not loosen in the dry weather?

Matt

 

[Paul Miller]

Hi Matt,

Once filled the canvas can't move much.

I'd go ahead and fill it as long as it is tight.

Good luck,

Paul

I've attached a picture of what it should look like when your done. Sooth and shinny. You only get that with hand rubbing.

 

[shelldrake]

Thanks Paul. And thanks for the inspirational photo.

Matt

 

[shelldrake]

Well, I waited until the humidity dropped and filled the canvas yesterday. No sags or wrinkles at this time! I rolled the filler on with a 3/8" paint roller. Three coats rubbed with a canvas mitt and smoothed with latex gloves at the end. Everything seemed to work well, but I do not have a smooth, shiny finish. It is dry to touch now, but there is quite abit of roughness (like sandpaper) in the finish. Did I not smooth it enough? Sanding will hopefully take care of the roughness. I used the whole gallon on the 15' boat.

Thanks everyone for your replies to my questions.

Matt