Had to take some time off building to work, but I have the boat as ready as its going to get for prototype phase. Thanks againt o all who helped or offered encuragement. Just waiting now for the glass I ordered to arrive. Also, the laquer coat I put on the boat to save on resin is causing strage reflections in the surface , it ins't as rough as it looks . This has been a trying experience so far, building a boat with nothing but journeyman's tools. The boat is cedar-strip, the ends are foam, coated in several layers of bondo to make them smooth and the correct shape. This seems to be a very good, (but extrememly wearing and time consuming) method of shaping the ends. I'm looking for any feedback I can get, and does anyknow know if I should rough-up the lacquer a bit before applying glass?
Thanks,
Rob
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Canoeing isn't a sport...its an art. Unfortunately, I am not exactly Michelangelo.
At this stage, saving resin shouldn't be your plan. While epoxy may bond to the lacquer, why take the chance. As Kaz said, sand the lacquer off, glass the whole thing - and go paddle. If you are happy with the boat, then you can worry about smoothing the ripples and getting that class A finish for molding.
believe it or not, your time and sweat equity will be more than the resin used.
The only reason I used the lacquer was a cedar-strip boat-builder's handbook I got my hands on suggested it... so now I have a dilemma, do I sand all the lacquer off or do I just rough it up, the book was unspecific as to whether the lacquer was supposed to be roughed up...but I have J. Kaz suggesting I should remove it, and I know he knows what he's doing......excuse me for a minute, I'm going go beat my head against the wall for awhile....
Canoeing isn't a sport...its an art. Unfortunately, I am not exactly Michelangelo.
For my wood-strip boat refurbishment I removed all the old glass (it was peeling anyway - poly not vinyl most likely), then 2 coats of squeegeed on epoxy (WEST systems), then a layer of glass (2 below waterline). The boat was as "true" as it was going to be before the first coat of epoxy (light sanding between coats / layers). AFTER all the epoxy / glass work was done it got many coats of spar varnish. Protects the glass for UV degradation and and easily (but annoyingly) restorable. I'll need to remove it to do any repair work though....
SO, if this is a boat to paddle, and you have enough layers of glass, just go paddle:) Or put on more varnish - just realize that you'll likely have to sand it all off if you are going to do any repair work or spray it before sanding it to the Nth degree to pull a mold off of it....
First, what kind of foam did you make the ends from? Some foam is not compatible with PE or VE resin while being OK with Bondo.
As far as sanding the finish off the wood, I encourage testing for material compatibility. Take some of your strips, glue up two 12" x 12" sections, treat one the way you have finished the boat (leave one raw wood), and then lay up the glass on the test sections.
Once the test pieces are done, hit them with a hammer and look for de-lamination. Then, maybe, try peeling the glass off the pieces.
A little testing can head-off a boat-size pile of never-hardening gue.
I will do the test strips. As for the foam, it is completely encased in the bondo, none of it is on the surface anymore, so the glass will only be bonding to the bondo...I don't see how it could still be an issue in this case, but if I'm wrong, please let me know!
Rob
Canoeing isn't a sport...its an art. Unfortunately, I am not exactly Michelangelo.
So - big question - Do you intend to paddle this for a long time, or is this to test/tweak and then pop a mold?
I ask, because to me it changes the level of effort at this point - and possibly the materials. For longevity, epoxy to bare wood will hold up much better and not delam, but Epoxy is 2 - 3 times the cost of Poly resin.
If this is just a plug, then all you really care about is getting testing done, getting a class A finish on the plug and pop the mold - you can get by with Poly resin, spray it with a high build primer like duracoat, and polish it out...to build your mold. As long as it doesn't delam before you build the mold, you are good.
Just remember that Epoxy will bond to polyester, but polyester will not bond to epoxy without a tie coat.
FWIW - the ester will move through the epoxy or bondo layer and may eat the foam. I had this happen on the Mentor plug - was all set and beautiful, and a delay in pulling the other half of the mold a few months... and suddenly there was a "hollow" where there wasn't one before. The vinyl ester resin (in gel coat) had gone chemically through the epoxy layer (and bondo) on the boat and in to the foam that it was shaped out of.
If your layers are thick enough though, it may not matter at that point.
This is purely to test/tweak and then pop a mold from it. Thanks for the info on the dissolving issue with the foam ends, I will watch for that. The book I'm using suggests using poly resins with this setup, so I am going to go with that. I'm not planning to paddle this much beyond just testing it out.
Canoeing isn't a sport...its an art. Unfortunately, I am not exactly Michelangelo.
In essence, there is nothing I can do to keep the ester resins from eating the foam? Aight, I guess I don't have much choice at this point but to do what I can do deal with it. Learning is fun, learning is fun, learning is fun....
Canoeing isn't a sport...its an art. Unfortunately, I am not exactly Michelangelo.
What kind of foam did you use for the ends? Polystyrene foam - ie:beadboard or extruded poly styrene will get eaten by the solvent in Polyester or Vinylester, but if the foam is urethane or minicell, then it will not get eaten and you are good to go.
I have some experience laying VE and PE resin onto shaped Styrofoam. Quite a number of times, it resulted in a big mess. I have tried many materials as barriers.
The only ones which worked dependably were:
1. Multiple layers of latex paint. I regret that I don't have my notes with me from those days, so I have no details regarding number of layers, drying time, and such.
2. Overlapping layers of heavy clear packing tape. The two tapes I have records on: (a) 3M Scotch 2" clear "mailing and storage" tape, and (b) Duck brand, "high performance" clear 2" packing tape (both from W-mart).
3. Wax paper on flat surfaces.
Over either the paint or tape, I would lay down five layers of Johnson's paste wax (yellow steel can) and two layers of PVA.
Of course, in all of my work, I wanted the glass to release from the foam. I am not 100% sure what the OP has in mind for his stems. Maybe, glass over the outside of the wood and Bondo/foam then leave the Bondo/foam in place when he glasses the inside of the hull? Maybe he will pull the Bondo/foam out before glassing the inside (this would result in a 100% glass stem).
Once again, my major recommendation is testing materials compatibility on smaller-than-boat-size samples. Just because something seems like it will work as a release agent, doesn't mean it will. Just because PE resin doesn't melt blue construction foam does not mean it won't melt white construction foam. And, so on.
, it ins't as rough as it looks 
. This has been a trying experience so far, building a boat with nothing but journeyman's tools. The boat is cedar-strip, the ends are foam, coated in several layers of bondo to make them smooth and the correct shape. This seems to be a very good, (but extrememly wearing and time consuming) method of shaping the ends. I'm looking for any feedback I can get, and does anyknow know if I should rough-up the lacquer a bit before applying glass?