My first glimpse of a drift boat was on the Cal Salmon as a kayaker in the late 70s - i was intrigued by the way the boat rode through the wave trains and could handle the water. I got a better look a bit later on a couple of Rogue trips, watching them through Blossom Bar... I thought I'd like to try that. The idea of building one was cemented a few years ago after a visit to Andy Hutchinson's shop and seeing his build of a decked boat in sapele - what a beautiful boat. So as a start, I got Roger's book and built a model, getting an idea of how things went together and where the challenges might be. This spring, I traveled to Flagstaff to attend Brad Dimock's class, where I met an incredible variety of skilled folks, all interested in building - not to mention a shop to die for. Then it was off to Oregon and the wooden boat festival. I stopped in Bend, where I picked up a trailer and a bunch of great information from Mike Baker - now I had a trailer, and needed a boat. Materials were a bit of a challenge - I originally wanted Port Orford Cedar for the frames - in Bend, there's a reliable supply from Orepac, but in Victor, where I live, no such luck. I ended up with Alaskan Yellow Cedar for about $7/bf. Hydrotek was next on the list. McBeath lists it on their web page, but there was a 2 month wait, so I ended up getting mine from Edensaw. Following Brad's lead, I'm using epoxy from Resin Research. Now for the fun stuff...
Great info, thanks!
I tipped my boat on its side and put 6 oz on the sides. I used a 12 oz biax on the bottom. I did apply epoxy to plywood before, couple coats too and sanded first before the glass. From what I read it seals off gasses from the wood which causes blisters in the resin. I just closed a link to a good article on glassing
The sides with the 6 were really easy and fun to do and really came out nice. The heavy stuff on the bottom was tough, it took alot of resin to wet that out, and even after a few coats or so after the glass its still rough. I`ll do a couple more before the last coats with the graphite, but it has got costly with the epoxy to do the bottom.
I tried the plastic spreader and I did not like it at all. I stayed with the west system rollers cut in half on a 3" roller handle and a paint roller pan with a plastic insert. The rollers come in 2 packs 7" long so you get 4 rollers for $7 and one boat side use from each one. They worked the best for me and dont push the glass around like a spreader, but whatever works best for you is what matters.
There were not many bubbles when you roll unless you go crazy rolling back and forth, and even then not too bad. When you mix the epoxy there will be bubbles in it. I mixed about 6 pumps worth at a time, poured it in the pan, rolled it on and then tipped it off in one direction with a foam paint brush as I went with each batch.
I used the same cup to keep mixing batches, same roller and same pan insert to do one coat on one side. (when the side was done with a coat, I tipped the roller up and the next day it pulled off the handle and I used the same pan insert for many coats on both sides) Once that wet out coat was almost set up, it trimmed off easy with a razor blade. I used the 207 special clear for the sides. It came out really sweet and was very easy to sand smooth on the sides.
That 12 oz is really hard to work with, but it should be tough.
I agree with what Tungsten said about sealing first. After that I like to use the west system notched spreader to spread the epoxy when wetting out the glass (large notches) it seems to be about the right thickness on 20oz. glass to wet out the glass without too much resin. I use a roller for follow up fill coats.
The Laughing Loon site makes a big point about having the shop temperature high (85 degrees) when you wet out cloth so the boat is warm and cools during the process. He does that so the epoxy is thin and wets out the cloth easier. He also claims it minimizes bubbles. It's getting on winter here in the Rockies and I've been heating the shop to 55 or 60..
What have your experiences been with wetting out cloth in those sorts of temperatures?
The idea of the spreader or trowel is so you can push the epoxy into the bare wood,after the first coat is on its film thickness your building so rollers or whatever will work just fine.
Warm the shop then turn the heat down before you start,you can pre heat the resin in the house on a heat register.Or store it by the shop heater.If the hardener is thick heat that also.If i remember right for every 10deg celsius rise in temp the epoxy viscosity drops in half.
When mixing large batches of warm resin keep it in a shallow container and move quickly.
You can do a test,take a little of each heat it up really hot see what you get for viscosity and pot life.
Yes, per tungsten....small batches when doing large areas. Seems the warmer the resin, the faster it wants to go off. Past forums recommend pouring all the mixed resin out of the container and onto the surface and start spreading it to dissipate heat build up. This is where the notched spreader that Mike mentioned comes in handy. Another tip found in past forums is if you see areas where the glass cloth bubbles up, this may indicate too much resin, use a flat plastic spreader to scrape the bubbled area of excess resin and the cloth will lay down better. My 2 cents....and that's exactly what it's worth.
Forgot to add,slow hardener at 55F from what I've used its going to take 24 hrs or so.Slow is a room temp hardener.I usally add some fast to my slow when its cold so its more of a medium.This gets me 4-6 hrs to be tack free.
It was cold when I was doing mine too. I warmed up the garage but never got above 65 or so. If your painting, you could use the fast hardener, but I was hoping for a clear natural finish so I used the 207( slow special clear). I think my sides came out really nice. My only bad thing is some of my screws I sank just a little too deep, leaving little swell spots at the screw head, I thought the glass would fill them in but it didnt. I`m in Ca. for the week for a training class, but when I get back I`m gonna dab some resin on those screw heads and cover with clear packing tape to hold it on there, till I can sand it and It comes out with no shiny spot. 1st pic shows the screw heads covered over good after sanding, 2nd pic shows a shiny spot that didnt sand out. Seemed a shame to sand the shiny epoxy but its getting ready for many coats of varnish
Armed with all the good suggestions, I primed the bottom with epoxy and laided on a layer of 6 oz glass. The tips I got helped a bunch here, and with a warm shop and warm epoxy, things went smoothly. Moving the goop with a spreader, then finishing up with a foam roller worked best for me.
After the resin hardened a bit and the edges were trimmed, it was on to the next step. I'm building what I'll call a Baker Bottom, 'cause I got the idea and a bunch of tips from Mike. It involves including a sheet of honeycomb material in the layup. I did a bit of research before choosing a product - looked at Plascore, Nidacore and Corecell. Corecell has a good reputation among builders of bigger boats, but at $70 for a 24x48 sheet, it's out of my price range. Plascore was more affordable, but the shipping costs killed that deal. I bought the Nidacore from an outfit called Merritt Supply in Florida and got it shipped to Idaho for a total cost of $122. I cut the first sheet of Nidacore to rough shape, troweled on thickened epoxy to the bottom, wet out the surface of the Nidacore and laided it on.
In spite of the comments of others on this site, I didn't mark the location of the screws fastening bottom to the chine logs under this sheet of Nidacore, so I'll have to see just how good my metal finder is...
Neat idea,I know MIke has mentioned this before.Looking forward to seeing how its going to finish.
The honeycomb material has a much higher compression strength compared to the basic M80 Corecell foam.I think you made the right choice.
Well, my little metal finder
that does so well finding nails in recycled lumber doesn't do so well finding SS screws under 1/2" of Nidacore, so I'll have to hope my screw layout was consistent. After the Nidacore was attached to the bottom, the next step was to trim the margins. Since Nidacore is a honeycomb of plastic, it doesn't take well to machining - it would rather melt. Trimming the first sheet gummed up a multitool saw blade, so I picked up a Bosch serrated knife blade that was a major improvement. It still got a bunch of melted plastic on it that won't respond to acetone, so I'm puzzling over what I can do for cleanup. After the edges were trimmed, there were about a million little honeycomb cells around the edge that needed to be filled with thickened epoxy. My second batch wasn't quite thick enough and sagged a bit after an hour, so I dammed up the edge with some packing tape.
Since there's only 1/4" of wood on the bottom, installing the garboard plugs needed a special approach. I started by using a Forstner bit to rabbet out a recess for the flange
then followed up with a 1/4" hole through the bottom to act as a pilot for a 3" hole saw from the outside through the Nidacore layer. A pair of needlenose pliers worked great to clean out the hole
A 1" hole saw through the center finished the prep. I sealed the edges of the hole with thickened epoxy.
I thicknessed a piece of meranti down and cut out a doughnut to match the recess that I'd created
and coated it with epoxy, let it cure and then installed it in the recess.
The next step is a layer of 12oz bi-axial on top.
How will the outer chine attach. Flush with the nidacore?