Stem treatment ?

MGC

Scrapmaker
I just finished installing a canvas. As I was getting ready to tack the canvas to the stems I got curious about what If anything) folks were applying to the stems and or between the top and bottom layer of canvas.
What got me thinking about this was discovering that the entire top layer of my bedding compound was as hard as a rock. I am in the habit of putting bedding compound down under the first layer and then another layer when I pull the second layer over to tack it.

"The Bible" (The Wood and Canvas Canoe Stelmok/Thurlow makes a passing note about bedding compound.
Joe Seliga applied filler between the first and second layers but nothing under the first.
Building the Maine Canoe, Jerry Stelmok's book refers to applying filler, the same technique as Seliga.

I corresponded with a few folks I know that canvas canoes and found that there were a couple different approaches. Some don't do anything. Some use adhesive (Tightbond).

I searched here and found a few other approaches referenced.
These include bedding compound, mastic, Dolfonite (bedding compound), Tightbond III, Sikaflex...there is a long list of materials used. Some do not apply anything.

I'm starting this post to focus discussion about this topic:

  • Is it necessary to apply anything between the stem and the first layer of canvas?
  • Should there be something applied between the first and second layer?
  • Should it be a material that hardens completely and adheres (like the Tightbond III) or should the material remain somewhat compliant?
  • Is a layer of filler adequate? Is it OK to do nothing and then rely on the filler applied to the canvas to seal up the gaps?
  • What is the most preferred material to use?

For me, I tried a product similar to Sikaflex on the first stem and hated it. The stuff would not stay in place while I was pulling and tacking the canvas in place. It ended up getting on the canvas where I did not want it..
On the second stem I put down a light layer of 214 bedding ad found that it helped keep the canvas in place while I tacked it down. It stayed put and did not migrate....I also put it under the second layer and again it seemed like it really made it easier to tack the canvas. I did not apply much and I'll fill the gaps and cloth with filler when I do the rest of the boat .

I'm really interested to hear what everyone else does and recommends. I'm not sure that what I do is right and it's clearly not the only way.
 
Here is another technique to be added to your list. I've done about 5 canoes this way and know others who use it. I will fill and seal the stem with epoxy and/or epoxy + sanding dust because the stem always has lots of old tack holes, cracks, etc. Onto the stem goes a thin (1/2") strip of double sided tape, like outdoor carpet tape. Stretch the canvas over this and tack/staple it from bottom to stem tip. Once you are happy with this, put a second strip of double sided tape over it, and stretch the second side of canvas over it, and tack. Take some epoxy and a brush and saturate the canvas over the stem. Then mix sanding dust into the residual epoxy until it is very thick, no longer runny, and spread that over the stem, covering the tacks and filling in any imperfections. Take a strip of stretchable plastic that will not stick to epoxy (saran wrap, or the stretchy stuff they sell to wrap boxes), and secure it to the canoe a foot inboard of the stem, then stretch and smooth it all along the epoxy (massage with fingers, get rid of air bubbles), and while continuing to stretch, secure the plastic strip, i.e to a C-clamp on the deck. Several strips of tape across the plastic help hold things where you want them. This gives a very smooth, hard stem that will take paint, is "waterproof" and accepts the screws which hold the brass stembands. Tom McCloud
 

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Right or wrong, I've use SikaFlex 201 for many years. Adhesive sealer...
I haven't had any issues. Comes in a tube...easier to deal with than Dolphinite.

To make a "seamless" look after filling the stem areas, I will sometimes apply QuikFair the stem and sand it out...
 
That's two more. I forgot about the double sided tape technique. That is used by quite a few folks.
I also should have noted the Quick Fare....are you saying you apply this to the stem before you tack on the canvas or are you adding it between the first and second layers? Or, are you applying it after the second layer is folded over and tacked down?
I find that stuff impossible to sand..easier to file or grind. I do use it.....and have applied it to stems to smooth them and fill the holes a bit.

I think I might summarize all of these and add them to the KnowledgeBase at some. There are so many techniques in practice.....
 
I use nothing. I put plenty of filler on the canvas seam at the stems and I bed the whole stem band (I have seen some folks bed just the screws). I have not had a leak.
 
I bed the whole stem band, too.. I Use Dolphinite....generally the mahogany color. I think it blends in better than white or natural.
Just like my buddy Fitzy!
 
The method I was shown and practice uses carpenters glue, that tacks quickly. You can smooth it with the hammer face and it sets up quickly providing some extra hold as each layer is pulled over the stem and tacked or stapled. It can also be sanded lightly for a smooth stem face.
 
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