First stripper build: Prospector-16 Help & comments appreciated

[memaquay]

Well, to throw another opinion at you......I never glass the inside with one piece. Instead, i use the roll side to side, so on a 16 footer, I usually have three main pieces, then I glass the stems individually. My canoes are work boats, I'm not concerned about glossy finishes on the inside. I put all three pieces in, smooth them out and overlap the joints by about 6 inches. Then I roll the two end pieces back a bit and put the resin to the middle piece first. The benefit of this is it is a lot easier to work out any bubbles or creases, as you just push them to the end of the piece. Difficult to describe, I probably should have taken pics at some point.

As for fill coats on the inside....waste of time and epoxy. Fill coats do not add strength nor waterproofness, but they do add weight. You will be coating the inside and out with at least three coats of varnish. However, if you want the mirror like finish on the inside, go for it. Just remember, it will add one more sanding step as you polish up the fill coats. For a wet out coat, I just do a quick rough sanding so the varnish will adhere.

Or you could go totally rogue and paint the inside. I have done that with a few of my canoes. Red of course, but green is nice too.

 

[Kliff]

Jim: you're posts never make me feel bad. I was just joking. I never expected to be as good or as fast as a seasoned veteran builder right out of the box. I've been working with wood for a very long time, but never applied my skills to canoe building. With all of the unexpected "life's events" over the past 6 months, I'm actually fairly pleased with where I'm at. I am getting a bit nervous with Wisconsin weather. Really want to finish this fall. Don't want to be varnishing in the house, and I need to replace the propane tank to turn on the furnace for the garage. I could use temporary heat, but I'd rather not do that either.

I am planning to wet out cloth, double layer football, and second coat epoxy.

 

[Kliff]

Just reviewing some of the videos from the CanoeCraft workshop series. Stumbled on this:

Jim White was a runner-up in our Canoecraft on the Water contest. He started the canoe in the beginning of 2016 and finished it July 23rd 2017: "This was my first canoe of several. I hope."

A year and a half for first canoe. Man, I'm way ahead of schedule. I need to slow it down a bit

 

[memaquay]

Quit inter-nettin, lol, you'll finish in no time.

 

[Jim Dodd]

As for fill coats on the inside....waste of time and epoxy. Fill coats do not add strength nor waterproofness, but they do add weight. You will be coating the inside and out with at least three coats of varnish. However, if you want the mirror like finish on the inside, go for it. Just remember, it will add one more sanding step as you polish up the fill coats. For a wet out coat, I just do a quick rough sanding so the varnish will adhere.

So if you just do a wet out coat on the inside, and sand to varnish ? Aren't you sanding into the cloth ?

As far as water proof epoxy coating ? A film of 7 to 10 mills is recommended.

Epoxy Wall Grade Epoxy High Build Coating Zero VOC

Epoxy Product #1W a wall grade chemical resistant epoxy coating, a waterproofing, a seamless flooring system, industrial strength coating.

www.epoxy.com

If you look up System Three's recommendations ? They say 3 coats for a water proof coating.

https://cdn.shopify.com/s/files/1/1000/1906/files/New_Clear_Finishing_of_Outdoor_Wood_4.pdf?13498644902871608925

 

[memaquay]

Well I don't want to get into an internet debate Jim, but the article you linked is actually about coating wood, with no glass. That's two separate animals. The amount of resin needed to saturate glass is considerably more than a thin coat with a roller on bare wood. And if your contention was accurate, all composite canoes, such as kevlar, would have the weave in the inside hulls filled. They don't.

The sanding of the fill coat on the inside is a light buffing to encourage varnish adhesion; no glass is harmed in the process.

There are certainly aesthetic advantages to filling the weave on the inside. It looks great, and if that is a requirement, fill your boots. I filled the inside on my first canoe too, but that was the last one.

 

[Cruiser]

I wasn't going to weigh in on this, but what the heck.

My understanding is that most of the strength of the fiberglass/epoxy is complete at the first coat .. the rest are esthetics for the most part. There are still valid reasons to continue on with the 2 fill coats (dimples and bury), but those are for practical and personal reasons not strength.

If using more epoxy was better, stronger, sexier ... vacuum infusion would not be the premiere method of construction of high performance canoes IMO.

As far as sanding into the epoxy with one coat, that is also an esthetic choice, the epoxy only requires the sanding regime if you are looking for the glass smooth finish, all that is required for varnishing is a scuffing with 3M or similar abrasive pads.

So I guess I am pretty well aligned with Mems comments ....

 

[Kliff]

While I am a novice at canoe building, I do have a fair amount of glass experience, and education. Max strength comes only from FULL wetting of the cloth, with no entrapped air. It is true, that additional epoxy adds virtually no strength beyond this. Where it does get a little tricky, is achieving full wetting, with no entrapped air, especially going over a porous surface. Then, there's the durability or longevity of the structural component. Vacuum infusion, or some of the compression methods used in boat building, especially by Ranger strive to minimize extra epoxy, while still achieving full wetting, and eliminating entrapped air.

I guess at the end of the day, just like so many of you have said, it comes down to personal preference. I'm not looking to shave every ounce I can. I also want it to look as nice as possible. At the end of yesterday I had the inside glass in place, but it seemed no way in heck I'd ever get it epoxy ready. An hour and a half tonight, and it smoothed out nicely, and I trimmed it to the inside stem above the turn. I ran it over the stem in the bilge area, and am planning to trim and tuck that area as shown in the Bear Mountain videos. Should be done with inside glass tomorrow.

 

[Jim Dodd]

Differing Opinions make the World go around !

I'm just of the School of a filling the weave on the inside !

Cloth is nicely laid in !

Take a deep breath and go for it !

Good Luck !

 

[Cruiser]

An issue with opinions is that people get fact and opinion/preferences confused ... although I believe that the first epoxy coat provides all the strength, I still add the second fill coat, largely to give some extra protection from scratching.

I also kill the inside varnish shine with a final coat of matte finish varnish, on a sunny day the reflection can be very rough.

 

[jffdejongh]

This is great advice! I totally agree

 

[Kliff]

Well, the inside is glassed. Wetted cloth a little heavy. A cup of epoxy went in the grunge can. doubled the football, wetted the football, and filled the first layer. Going to be scraping the edge of the football and a couple spots around the stems first thing in the morning, then I'll be starting the trim work. I'm starting to feel like this thing might see the water yet this fall. After I took the last picture I realized I needed to squeegee one more time. Put the fill coat on a bit heavy.....Again. Another 3/4 cup in the grunge can.

 

[Jim Dodd]

Excellent !

Now it gets to be a lot more fun !

I always relaxed after finishing the inside !

 

[Roybrew]

Looks fabulous Kliff! You used a football patch on outside and inside?

 

[Kliff]

Yeah, Roy. Could be a bit of overkill. First canoe, not going to be doing a lot of distance portaging. I'll put more thought into next canoe glass use. I was concerned about abrasion (inside and out) and the mere thought of oil-canning gave me tremors. Not sure how big of a concern that is, but I literally had nightmares that it would end up looking like one of those cheap plastic canoes, all bent out of shape, strapped to the top of a car. Heck, I have one that developed a "reverse rocker" as I call it.

Still trying to decide between caning the seats, or using a weave similar to the pictures Jim has posted with the synthetic snow shoe webbing. I know, personal preference. To me, caned looks "fancier", square weave webbing looks "more traditional".

I have the in/out whales rough cut. Need to scarf join, cut scuppers, taper ends, etc. Hoping to get those done this week at work, and seat frames and thwart as well.

 

[memaquay]

I've built over 30 of these things now, I've never had one oilcan with just the single layer. Having said that though, the extra layer on the inside will greatly enhance the strength of the hull. The exterior second layer is mostly just for abrasion. The only two times I have had serious damage in white water, the inside layer of glass split open while the exterior stayed intact. If I had an extra layer on the inside, it probably would have remained intact. If you are not concerned about weight, I think it is a fine idea to put that interior layer in. Total weight added will not be a lot, probably just a two or three pound at most. In fact, on my next build, I think I will add an interior layer. Hope to start it in the next couple of weeks.

 

[Jim Dodd]

Mem and I have differing views on this, I'll just let it go at that.
Your hull will stand the test of time and abuse !
I have personally witnessed the down falls of single layering !
Thankfully I had Duct tape to help a friend out of the BWCA !

The extra layer on the outside is sufficient !
Again this is your canoe !

Looks Great !

Jim

 

[Roybrew]

I used single layer on inside, and football patch with single layer outside. And when I raise up and back down quickly I can see the bottom deflect a little. I do worry about it, but I am a little chunky. I figure if it cracks I'll fix it. My wife will save me if it sinks, I hope.

 

[Jim Dodd]

Tandems definitely require a thicker bottom, they are wider, and generally carry more weight.

Most everything I build is solo, and I still add the extra layer to the outside .

Jim

 

[Roybrew]

Tandems definitely require a thicker bottom, they are wider, and generally carry more weight.

Most everything I build is solo, and I still add the extra layer to the outside .

Jim

Eeww I was afraid to ask.

Yep Kliff, good idea to add that extra football patch to the inside. Your canoe is looking good.
Roy