two ? gaps and filler cure time

[Rick L]

the replacement ribs are going great so far, so with the small amount of planking to replace, its time to plan ahead for finish work, I still hope to sail this mid September, but I think the window is closing fast.

first question, there has been shrinkage of some of the original planking leaving several small gaps between the boards, mostly the width is between the thickness of a dime and a penny. Will these swell shut during the finishing process - or do I have a bigger issue?

second question -reading the books and some web sites the cure time for the filler is 3 to 6 weeks. that is quite a variation. Is that due to enviromental concerns - a dry summer Vs cold winter? or is it the formula? How can I shoot for the 3 and still hope for good results?

thanks
Rick

 

[Rob Stevens]

the replacement ribs are going great so far, so with the small amount of planking to replace, its time to plan ahead for finish work, I still hope to sail this mid September, but I think the window is closing fast.

first question, there has been shrinkage of some of the original planking leaving several small gaps between the boards, mostly the width is between the thickness of a dime and a penny. Will these swell shut during the finishing process - or do I have a bigger issue?

second question -reading the books and some web sites the cure time for the filler is 3 to 6 weeks. that is quite a variation. Is that due to enviromental concerns - a dry summer Vs cold winter? or is it the formula? How can I shoot for the 3 and still hope for good results?

thanks
Rick

Q1 No issue. Gaps happen with all builders/restorers. Timeless axiom; Wood moves.

Q2 It all depends what the filler is made of, as well as with the conditions it's exposed to. Traditional fillers are oil based, so take a long time to cure. Follow the manufacturer's recommendations to avoid any longer term issues with paint not adhering, etc.

 

[Dave Osborn]

Rick,
GAPS HAPPEN..... As far as I know there isn't much you can do, short of replanking to solve it. Large gaps won't swell shut. Well, maybe they will swell some. Not sure what you are restoring but, I notice gaps more so on Huron and Old Towns than other makes for some reason.
Its nothing to worry about. Just try to keep clean feet to prevent sand from getting into the gaps as best as you can. Don't not enjoy your canoe by being over protective of it.

I don't know of any way to accelerate the cure of filler. If there was a good way to predict it or make an early cure, it would be part of the normal protocol for filling. Probably the best way to have a shot at three weeks is to have good dry air circulation to enhance the evaporation of solvents. Even then it may be potluck on the cure. It may be bad to rush it, too. Some have hypothesized that dried paint over uncured filler can lead to problems.

For faster cure and resulting in weight reduction, you may consider Ekofill from Stewart Systems. It's a water-borne, fast drying filler used on fabric aircraft wings. I've had great luck with it and use it exclusively unless otherwise instructed by my customer. It was a process developed by former WCHA president, the late Chris Merigold. The process has been documented by Mike Cavanaugh on this forum, however the name of the product has changed from Cecofill to Ekofill. Do a search on Cecofill and see Cavanaugh's process.

 

[Jon Bouton]

Hey all,
We used a West Systems epoxy mixed with a West Systems lightweight filler when we filled the canvas about 10 years ago. Spread it with plastic blades (like putty knives and sheetrock knives) It cured overnight and we were added a second layer to add some depth and complete the filling process (after 1 layer, we Could still see the texture of the canvas). This was my first and only time , but fairing seemed to go well and I've had no trouble with paint (Interlux Yacht Enamel) sticking.
Because Dave and Rob didn't mention an epoxy filler and they have a lot of experience, I'm wondering what's the drawback, other than it is not traditional, of using an epoxy mix. Interested in any comments. -- Jon

 

[Dave Osborn]

I've heard of epoxy being used on canvas, but don't know of anybody that ever used it. Not sure why....? Does it bond to the planking??

An alternative to these ideas, I know a guy that just varnishes raw canvas. He uses hardware store spar varnish. It takes about 2 gallons to completely fill the weave. Seems to work good. I suspect that the canvas sticks to the planking, so I suppose that a heat gun may be needed for removal or repairs.
He usually makes birchbark canoes in a very traditional way, but tends to lean to the left when doing work on modern wood/canvas....but it works!

 

[Rob Stevens]

I saw a canoe filled using epoxy by Roger Foster (Carlisle Canoe Co.) a couple of weeks ago. I was surprised at how flexible the test strip remained having thought epoxy would be brittle. Not sure how/if Roger did anything to prevent adherence of the canvas to the planking. The puckers around the staples were somewhat stiffer, so might be a challenge to get the out-wale to close up the gap. Perhaps each pucker could be flattened with a clamp before installation of the outer rail.

I seem to recall the canoe was slightly heavier than usual.

 

[MikeCav]

Here is the post of use of Cecofill http://forums.wcha.org/showthread.php?1701-Cecofil-amp-Latex-Filler-method&highlight=cecofil I'm not sure I'd use epoxy for fear of gluing the canvas to the boat!

 

[Dave Osborn]

Mike, Did you use the Cecofill on the TACONIC??
FYI< I have the Ekofill system on my every day user/guide/tripping canoe..... A Thompson Indian c.1938 (Big Red)
I have deliberately NOT put it away when not in use to see how the elements affect the filler system. Other than being under cover in the winter, the canoe is outside on a rack, or most often on my Tahoe. This is the second summer of that and I see nothing detrimental going on to the filler or paint. A year and a half is a short time so I'm planning to continue to leave it in the weather to see how durable the system is. I can tell you that I've hit some stumps and rocks that I was afraid the canvas would have torn, but it has not. The schtuff is tough. (IMHO)

 

[Rob Stevens]

I'm not sure I'd use epoxy for fear of gluing the canvas to the boat!

Someone suggested waxing the outside surface of the planking before canvassing, then applying epoxy.

 

[Jon Bouton]

I can't tell if the West Systems epoxy & filler glued the canvas to the planking where the canvas is tight on the planking, and I'm not about to slice into it to find out. This canoe has some recurve near the bow and stern where, try as hard as we could, we could not get the canvas tight on the planking. No wrinkles, you can't see it, but if I press the epoxy filled canvas on those 4 areas of the canoe, I can tell there is a small gap between plank and canvas. Anyway, those are spots where I can definately say the the canvas is is not glued to the planking. I seem to recall we put a coat of boiled linseed oil on the planking before adding the canvas. I wonder if that might prevent the dreaded glue affect.

I also was a bit frustrated with the finish on the stems. The ends of the canvas, filled, were rougher than I would have liked. I did play around a bit with stem band placement to try to cover it up.

Bottom line, It seems to work for me. After attending this last assembly and seeing so many restored boats with no imperfections, I know this canoe is nowhere close, but I do use it whenever I can (which is not enough)

Thanks for comments on non-traditional fillers. And good luck, Rick L., on your re-canvasing and finishing.

 

[MikeCav]

Dave - no I used a traditional filler (Rolands) on Taconic. I used the Cecofil/spackling on ALDA and was quite happy with it.