Cedar Strip Canoe - Could I get a little help from my glassen buddies?

[jasoutside]

Hello Gentlemen!

So check it out. This is a ceder strip canoe that our students here at the high school have been working on for two years now. They are doing a fantastic job! Especially considering they have never done anything like this nor has our shop teacher, all rookies! Me? I try to sneak down to the shop when I can but don't do much other than drool on it and offer a tid bit of advice when the opportunity presents.

Here are some photos of where they are at as of today...

What you are looking at represents a tremendous amount work completed, huge props to those students! She'll be a beauty on float day

Now, they are prepping to lay glass in a day or two and I have a couple concerns. I just want to make sure they are headed down the right path here.

You can see there the dark spots on the hull. They have tried to fill in some voids in the wood by using this System 3 Epoxy...

Now, at this point, they have been instructed to begin laying glass.



Concern/Question #1

On those dark spots...

I'm a little concerned that those dark spots may show up once the glass is laid?? I realize that in the glassen process the wood will be wet out, then the glass, then wet out, and during the first wet out, it should/may blend in? I'm just a bit fearful that there will be dark splotches showing through.

Fear justified or unjustified?

Should they sand out the blotches? Should they put a full coat over the whole boat, to blend in from there (so to speak) and then carry on with glass work?



Concern/Question #2

The boat is obviously going to have a few very small voids here and there given the construction. Should they take the time to make it totally, perfectly flat? Get rid of any sort of voids? The reason I ask is I am just a bit concerned that there may end up being "air bubbles", you know, that sort of situation. This is a straight up glass man question that I have no idea if this could happen. Please know any "voids" are very small. I can just get a piece of fingernail in a few of them.

Should I be concerned out this? Or, not so much.

It seems at this stage, right before the glass goes on, this hull needs to be spot on. Kinda seems to me like a one shot deal once the glass goes down.

But what do I know, just a metal banger eh.

I have just a follow up question or two but let's start here eh?

Thanks

 

[andgott]

Re: Cedar Strip Canoe - Could I get a little help from my glassen buddies?

Looks like they are doing a GREAT job!!

Odds are, the darker spots won't show up- BUT, If it were my project, I'd sand them down a bit anyway... That way you can be SURE. Small 'voids' wont be a huge issue- I am assuming that they are in the joints between the strips, and are on the surface, not all the way through. As you know, the resin is fairly viscous, and it'll fill them when you wet out the glass.

I wouldn't bother with a full coat of resin before glassing- You are going to want to coat the hull well, lay the glass, then wet it out... You'll be using some pretty fine glass cloth, which wets out nicely and conforms really well to curves. It's actually kind of fun to work with, once you get going, though it can be a bit frustrating. Have PLENTY of resin ready to go- And use the proper equipment- Rollers are a MUST for the wet out. Since it seems you've got a team of students working on it, have some applying, and others standing by to mix more as needed. You'll be amazed how much that girl soaks up!

Keep us posted!

 

[Ned L]

Re: Cedar Strip Canoe - Could I get a little help from my glassen buddies?

Great looking job. I would recommend you also ask your questions on the WCHA website (Wooden Canoe Heritage Association). You won't get any better canoe advise than there.

 

[Woodonglass]

Re: Cedar Strip Canoe - Could I get a little help from my glassen buddies?

This will help...
http://www.youtube.com/watch?v=evKiJNFiYIk&feature=related

 

[Decker83]

Re: Cedar Strip Canoe - Could I get a little help from my glassen buddies?

WOW!!!!
How great is that. Wish my high school had a program like this when I was going HS. I may have been a boat builder instead of a insurance agent. That is great.

I have not worked with epoxy and wood before, but I have used stain on wood many of times. I would try to sand out as much as posible of those stains. I have seen wood with stains spots on it and it did show through even using the same stain over it again.

I would try to use some scrap cedar and put the filler that was used on it and let it dry and then put the epoxy over it and see what happens.

About the small voids, the cedar may swell some with the epoxy and close them for you. I know it does with water. Just a thought.

 

[Decker83]

Re: Cedar Strip Canoe - Could I get a little help from my glassen buddies?

I sure would love to see this finnished. It looks great now.

 

[jasoutside]

Re: Cedar Strip Canoe - Could I get a little help from my glassen buddies?

Thanks for chippin in fellas! Hey, I gave the Ind. Tech teacher and students the link to this thread so they'll be keeping close tabs on your advice. Thanks!

 

[chriscraft254]

Re: Cedar Strip Canoe - Could I get a little help from my glassen buddies?

The patches they have done should be sanded down smoooth. they will not show. Apply coat of epoxy to canoe. Then apply roven cloth material with epoxy coat. A three inch roller works well. Start from the center and work your way out and down the canoe. Then apply your filler coats and brush/tip the finish.

Will they be adding keel strips to the two ends for when bumbing off rocks? Will there be varnishing layers after epoxy?

 

[jasoutside]

Re: Cedar Strip Canoe - Could I get a little help from my glassen buddies?

Will they be adding keel strips to the two ends for when bumbing off rocks? Will there be varnishing layers after epoxy?

Yup, keel plates are going to be installed.

Varnish? We haven't talked about it yet but they must be headed that way. I'll check in with them.

_________________________________________________________________

Guys, thanks for stopping by and chipping in, appreciated!

K, next questions...

#1

4 oz. good for fiberglassen this project? I do believe that is a good choice but please correct me if that's no good.



#2

The students are going with West System 105/205...

http://www.westsystem.com/ss/epoxy-resins-and-hardeners

What amount (how many gallons) do you suppose it would take to do the job, outside and inside? 4 coats about right?



Thanks!

 

[Woodonglass]

Re: Cedar Strip Canoe - Could I get a little help from my glassen buddies?

Standard Canoe Cloth is 6 oz and sometimes they double the bottom to allow for the "Knocks and Scrapes"

 

[jasoutside]

Re: Cedar Strip Canoe - Could I get a little help from my glassen buddies?

Howdy fellas!

Check this out and let me know what ya think?

Whatcha think?

 

[Woodonglass]

Re: Cedar Strip Canoe - Could I get a little help from my glassen buddies?

This is a great link that "Shows and Tells" the steps needed.
http://www.cedarstripcanoe.info/fiberglassing-outer-hull/

They are planning on Flipping her and sanding and glassing the inside too...Correct? This has been a life long dream of mine and I have 3 books on the subject and multiple plans. Done tons of research and studying. Remember that epoxy has NO UV protection so after the last filler coats of epoxy have been applied to the cloth, I'd highly recommend 3-4 coats of a Quality Marine Varnish for the UV protection. Also they might want to consider cutting a Football shaped piece of glass to lay on the bottom of the hull as an added protection for Scrapes and Bumps on the bottom. This is a common practice. What oz cloth are they using? What Epoxy are they using? What Viscosity? They should drape the cloth the night before and smooth it as much as possible and then let it relax over night. This really helps avoid wrinkles. Common practice for applyin the epoxy is to pour it along the keel line and let it run down the sides and use a roller or bondo spreader to wet out the cloth. Prolly best to put heavy paper or plastic under the canoe to catch the drippings cuz there WILL be a lot. Looks like they have a lot of sanding to do. The Cedar laced filler will show through if it is not sanded off.

 

[fishrdan]

Re: Cedar Strip Canoe - Could I get a little help from my glassen buddies?

I would try to use some scrap cedar and put the filler that was used on it and let it dry and then put the epoxy over it and see what happens.

That's a very good suggestion, test it out on some scrap to see how the cedar dust thickened epoxy affects the finish. I have a feeling it's going to be noticeable. I'm just spit-ballin here, but maybe your first coat of epoxy needs to be thickened a bit with cedar dust like the filler was, so it helps blend in the area's where the thickened epoxy was applied. Test it out and see how it looks.

It's too late for this now, but anytime I'm filling a hole/crack (and don't want the filler going into the wood grain along side the filler) I tape off the problem area with painters tape, then apply the filler. The tape keeps filler out of the wood grain so it's less noticeable. After the filler has hardened, trim the excess filler off the tape with a razor blade or sand it down, then remove the tape. The fine line of filler left after removing the tape is easily sanded down to the wood's surface.

One problem you should be aware of is the epoxy coated cedar is going to be a lot harder than the raw cedar. Sanding down the splotches will need to be done carefully so the raw cedar around the epoxy remains level. (IE: don't create a low area around the epoxy splotch while trying to sand out the splotch.

 

[jasoutside]

Re: Cedar Strip Canoe - Could I get a little help from my glassen buddies?

This is a great link that "Shows and Tells" the steps needed.
http://www.cedarstripcanoe.info/fiberglassing-outer-hull/

Great link, thanks WOG!

They are planning on Flipping her and sanding and glassing the inside too...Correct?

Yup!

Remember that epoxy has NO UV protection so after the last filler coats of epoxy have been applied to the cloth, I'd highly recommend 3-4 coats of a Quality Marine Varnish for the UV protection.

I do believe the Epoxy they are using has UV protection. Why do I think that, I dunno, I want to say I was reading the info on the can. I'll confirm that and if not we'll certainly want varnish as well.

Edit: I just checked to be sure. We need varnish.

Also they might want to consider cutting a Football shaped piece of glass to lay on the bottom of the hull as an added protection for Scrapes and Bumps on the bottom.

Great idea!

What oz cloth are they using? What Epoxy are they using?

4 oz. and post #9

They should drape the cloth the night before and smooth it as much as possible and then let it relax over night. This really helps avoid wrinkles. Common practice for applyin the epoxy is to pour it along the keel line and let it run down the sides and use a roller or bondo spreader to wet out the cloth. Prolly best to put heavy paper or plastic under the canoe to catch the drippings cuz there WILL be a lot. Looks like they have a lot of sanding to do. The Cedar laced filler will show through if it is not sanded off.

Excellent suggestions!

That's a very good suggestion, test it out on some scrap to see how the cedar dust thickened epoxy affects the finish. I have a feeling it's going to be noticeable.

Yah, they actually ran a bit of a test and yup, it'll be noticeable. Hopefully not too bad though.

One problem you should be aware of is the epoxy coated cedar is going to be a lot harder than the raw cedar. Sanding down the splotches will need to be done carefully so the raw cedar around the epoxy remains level. (IE: don't create a low area around the epoxy splotch while trying to sand out the splotch.

Yah, they are currently working through this part of the process. Little tricky to be sure.

Thanks a ton for chipping in fellas!

 

[1988Starcraft]

Re: Cedar Strip Canoe - Could I get a little help from my glassen buddies?

I've been doing my own boat rebuild project (an aluminum Starcraft) but have become interested in what everyone else is doing. While I'm a novice with aluminum, I've worked on all composite racing canoes and some made out of cedar strips for over 30 years so I have some experience that might be helpful. With a racing canoe, stiffness is good and weight is what you don't want. In reading through your thread, you've got a lot of great suggestions. There are a lot of canoe racers in MI so you should be able to find someone there to help if you want to. Racers use their equipment a lot and you need to know how to make repairs. The link showing the guys glassing their wood strip is great. You mentioned earlier that you intended to put multiple coats of the resin on before and after the glass. All the resin does is glue the glass in place. AThe people on this forum tend toward overkill when it comes to building. With a canoe, that isn't necessarily the best thing to do because a heavy canoe isn't fun to paddle or take on and off the car. With any good composite canoe, there is usually a core in the bottom of the hull and in a few ribs for stiffness but all the strength in the hull comes from the glass itself. In older racing canoes that were made from fiberglass, you could see right through the hull between the ribs because the glass and resin were very thin but strong. The guys in the video only used three coats of resin: the one that wet the surface, the one that sticks the cloth down and the finish coat. You can probably get away with just the first two because once the cloth is filled and all wet, any resin you add is just more weight that will be sanded later. However adding that last coat does protect you from having the glass too dry in spots so for your application it's probably OK. You've got lots of kids to do the sanding. Racing canoes (and many other all composite hulls) are vacuum bagged. This process sucks ever possible drop of excess resin out making the boat as light as possible without sacrificing strength. In my early boat repair attempts, I also thought more resin can only be better. What painting on more resin did was cause me more sanding later on. it only adds weight not strength. Adding more resin also doesn't make the boat look better. It's the sanding process that makes the boat have that glasslike finish (if you don't use a mold). When repairing a cedar strip boat, I've used wet sanding down to 600 grit and it comes out very smooth but not like glass. For that glasslike finish you'll need to go even farther. Go as far with the sanding as you want based on how the boat looks after each step, but don't just add a few more coats of epoxy in hopes of make it look better. That just gives you more stuff to sand off. With enough sanding, cedar strip canoes can look beautiful. It's all in the elbow grease.
After your canoe is done, it will be beautiful but unfortunately it will require more attention than a fully composite canoe. No matter how careful you are, expect damage that cause cracks in the glass. You'll want to be very alert for any cracks no matter how small. They'll let water in and the cedar will get and stay wet. Then it turns black and you'll have a repair job on your hands. If you repair the cracks quickly, the boat will stay looking nice. Repairs can vary from a little sanding with some resin filler that requires more sanding to fully blend it in, to sanding it down to bare wood and adding a glass patch. Obviously you'll need to dry out the area near the crack before repairing it.
A trick I've learned over the years with repairs is that if they're small you can get a pretty good finish by stretching Handi-Wrap over the wet resin. There's something in Handi-Wrap that keeps it from sticking to the resin. Don't try any other brand of clear food wrap without testing it first because it could stick to the boat and make a big mess. Use masking tape to hold down the edges and stretch it tightly over the repair. If you're careful and don't use too much resin (the Handi-Wrap squeezes out any extra and it will get onto parts of the hull you don't want it on), the Handi-Wrap trick can avoid the need for sanding all together although you usually need to do a little sanding to make it look perfect. It's kind of like the vacuum sealing used by the boat manufacturers. I've done repairs this way that wound up shinier than the original hull.

Good luck and enjoy paddling a beautiful cedar strip boat. 1988 Starcraft

 

[jasoutside]

Re: Cedar Strip Canoe - Could I get a little help from my glassen buddies?

Thanks for stopping by 88!

We are actually here at the school right now - sanding.....

We are hoping to have a couple of coats of epoxy laid today.

 

[jasoutside]

Re: Cedar Strip Canoe - Could I get a little help from my glassen buddies?

Well, after about 3 hours of 4 guys sanding we are a little bummed.

We wiped er down with mineral spirits and can still see those splotchs.

Lots more sanding needed.......

 

[1988Starcraft]

Re: Cedar Strip Canoe - Could I get a little help from my glassen buddies?

1988 Starcraft again. I'm not sure you should be too worried about the blotches. What I think has happened is some of the resin you used to create them in the first place has soaked into the wood leaving it dark. If I'm right (and this is just a theory) you'll have to sand away the resin soaked wood in order to get back to the light color you have everywhere else. That might leave flat spots or thin spots in your hull neither of which are good. I think the rest of the hull will turn dark when you put the first coat of resin on it and you won't see the blotches any more. It's a good idea to sand them smooth but I don't think you need to try to get rid of them altogether. Here's an idea to prove my theory. Take some scrap cedar and put a little resin on half of it and let it harden. It should look darker than the uncoated half. Come back and coat the entire piece and let it harden. If you still can see the initial patch, I guess you'll have to keep sanding. If not, you have confidence that you can proceed with applying the first coat of resin and glass on the canoe without worrying any more about the blotches once they're smooth. Don't get the kids too worn out sanding yet. There's plenty more to do later on. Good luck.

 

[Snapset]

Re: Cedar Strip Canoe - Could I get a little help from my glassen buddies?

I built a cedar strip canoe a few years ago. Great project, and a lot of work. Congratulations to the students for their work. They should be proud of it. (They are almost halfway done)

Regarding the dark colors form the resin: The cedar is very porous and absorbs the resin well. The resin sets up, it does not "Dry" or "Evaporate". Whatever is applied to the boat will stay with the boat. So if you apply more resin to the wood before glassing, I feel that you will likely not see noticable shade differences after glassing. What you will want to match is similar amounts of resin absorbed by the wood.

I glassed my canoe without prewetting the wood, but I wasn't concerned about the color patch issue you have.

So this is my advice: Sand the cedar, dampen it with water to rase the grain, finish sand one more time,t according to and let it dry for a day. Wet the wood with epoxy, immediately apply the glass cloth, and epoxy it according to instructions.

Once you wet that wood, the beauty of the cedar will pop out and give you the inspiration to finish the project. It will be beautiful.

Don't waste a lot of time trying for perfection. Save your energy for the seats, decks and gunwale strips. That is what you will be seeing as you paddle anyway.

 

[Woodonglass]

Re: Cedar Strip Canoe - Could I get a little help from my glassen buddies?

Any updates???