Cedar Strip Canoe Build

[shipwright]

Back to the earlier question about the jig.
Yes you have it right you establish the line on the face and then plane off the part outside the lines.

In any boatbuilding I have ever done only fully waterproof glues are used.
Epoxy, resorcinol, urea formaldehyde. No hide glue, no PVA.

But I've never built a canoe and as I say they may not require the same degree of water resistance. ..... Still wouldn't use it.

[newportcycle]

Ive read some blogs where folks used Hot glue, not sure if it was "hide" glue or not. IMOP, there would be no reason Hot glue would not be sufficient, you will need to make provisions for keeping the strips tight to the forms either with clips or straps, this is would a critical step you will also have to use screws in spots or be very creative in your clamping. In reality all you are constructing is a fiberglass form the cedar strips will give no real strength to the hull.

I would definately not use epoxy, pot life is to short and it would be a bear to apply to the coves and not get it everywhere. Wood glue is sufficient, use it moderately, any that runs now will have to be scraped or sanded off later.

[shipwright]

I won't argue about this but:

1) IMHO when you build something that will go in the water, you use waterproof glue regardless of what you are skinning it with.
2) I also disagree that the cedar adds nothing to the strength of the hull, unless of course you are laying up 1/4" of fiberglass.
3) Epoxy needs not be messy and while pot life can be an issue, it is easy to work quickly once you become familiar with the material. This is how you apply it to the edges of strips. There should be little or no "squeeze out" and as it's not runny , it can be cleaned on the spot and reused, leaving very little sanding later.

Here is a blog I did on some epoxy handling tips.

Again, I don't want to start an argument. These are my opinions, based on my experience. I'm just trying to help.

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[frank81]

I won't argue about this but:

1) IMHO when you build something that will go in the water, you use waterproof glue regardless of what you are skinning it with.
2) I also disagree that the cedar adds nothing to the strength of the hull, unless of course you are laying up 1/4" of fiberglass.
3) Epoxy needs not be messy and while pot life can be an issue, it is easy to work quickly once you become familiar with the material. This is how you apply it to the edges of strips. There should be little or no "squeeze out" and as it's not runny , it can be cleaned on the spot and reused, leaving very little sanding later.

Here is a blog I did on some epoxy handling tips.

Again, I don't want to start an argument. These are my opinions, based on my experience. I'm just trying to help.

[ATTACH]23156[/ATTACH]

As a canoer who works for a boat manufacturer (have worked in fiberglass and aluminum, big and small) I would agree 100% with everything Shipwright has said here.

On 99% of fiberglass vessels, the stringers and ribs give it strength. You only glass over them to seal out water and prevent rot. The hullsides are a glorfied skin supported by the ribs and you would have hull failure unless you built a solid FG hull...in whch case you would skip most of the beautiful work you've done so far and just build a positive mold.

Always use waterproof glue. Always use resin when your wallet allows. Your FG will eventually develop cracks and moisture will creep in. Especially if you are canoing anything other than flat water.

If you have excessive squeeze out of resin you are creating work and wasting lots of money. I use a plastic scraper to put down as thin of a layer as possible on the workpiece, dab a small amount on my FG matting and work it (ball it up repreatedly) until it's saturated, then lay it on the workpiece and scrape the bubbles and wrinkles out. It takes about 2-3 minutes to work a 2'x 2x square of mat so patience is needed. It helps to have a partner if you're working on a large surface area so you don't have to race the clock.


As for stem v. no stem...IMO a stem is mostly cosmetic on any boat that is not being run on plane....used to hide ugly butt welds, etc. In the case of a canoe, your enemy is not chop beating against the hull it is sliding against rocks, sand, etc. In that case you add a sacrificial skid plate - I use a 2x3 sheet of fiberglass but if you want it to last longer a lot of people like kevlar.

[algale]

As a canoer who works for a boat manufacturer (have worked in fiberglass and aluminum, big and small) I would agree 100% with everything Shipwright has said here.

On 99% of fiberglass vessels, the stringers and ribs give it strength. You only glass over them to seal out water and prevent rot. The hullsides are a glorfied skin supported by the ribs and you would have hull failure unless you built a solid FG hull...in whch case you would skip most of the beautiful work you've done so far and just build a positive mold.

Always use waterproof glue. Always use resin when your wallet allows. Your FG will eventually develop cracks and moisture will creep in. Especially if you are canoing anything other than flat water.

If you have excessive squeeze out of resin you are creating work and wasting lots of money. I use a plastic scraper to put down as thin of a layer as possible on the workpiece, dab a small amount on my FG matting and work it (ball it up repreatedly) until it's saturated, then lay it on the workpiece and scrape the bubbles and wrinkles out. It takes about 2-3 minutes to work a 2'x 2x square of mat so patience is needed. It helps to have a partner if you're working on a large surface area so you don't have to race the clock.


As for stem v. no stem...IMO a stem is mostly cosmetic on any boat that is not being run on plane....used to hide ugly butt welds, etc. In the case of a canoe, your enemy is not chop beating against the hull it is sliding against rocks, sand, etc. In that case you add a sacrificial skid plate - I use a 2x3 sheet of fiberglass but if you want it to last longer a lot of people like kevlar.

I'm confused. I was talking about glue for edge gluing the cedar strips. In canoe building the strips are 1/4 inch wide and there is a 1/4 inch cove milled into one edge and a 1/4 inch bead milled on the other. Glue goes in the cove. No fiberglass at this stage.

[JPG]

Fiberglass (resin?) IS de glue. IIUC;) Appears I did not UC! See de next post!

[shipwright]

Polyester resin (Fiberglassing resin) does not stick to anything but other polyester resin as in multiple layers in a fibreglass layup. It does not work as a glue and never worked well as a resin for applying 'glass cloth to wooden boats even though several big builders used it that way in the past. (Tollycraft for one)

Al, the planking on my boat that you see in the photo is ~5/16" thick and was actually beaded and coved using the same router bits as used for canoes. In the case of my boat it was covered by two layers of 1/8" cedar on opposing diagonals.

Just to clear things up....

[algale]

Polyester resin (Fiberglassing resin) does not stick to anything but other polyester resin as in multiple layers in a fibreglass layup. It does not work as a glue and never worked well as a resin for applying 'glass cloth to wooden boats even though several big builders used it that way in the past. (Tollycraft for one)

Al, the planking on my boat that you see in the photo is ~5/16" thick and was actually beaded and coved using the same router bits as used for canoes. In the case of my boat it was covered by two layers of 1/8" cedar on opposing diagonals.

Just to clear things up....

Thanks, Paul. Is that Friendship you are referring to?

[shipwright]

Yes, that is Friendship in the early stages in the photo.

[frank81]

Sorry I should clarify that I use epoxy resin most of the time unless I'm laying up a large, glass only part. In the past that would be an extremely wasteful decision but the market has changed and the price increase over polyester is not near what is used to be. The advantages of epoxy resin more than outweight the premium right now.

For a canoe that does not contain flotation foam I would not hesitate to skip poly altogether and use expoxy resin throughout, including as a glue. Fiberglass canoes are good for flat water and ocean but inland you are going to want the extra strength and flex. I have a friend with a high end poly resin - fiberglass canoe he's sunk it twice now on difficulty 1 or 2 streams...he's not allowed to bring it on float trips anymore, I loan him one of mine or he doubles up.