Thread: GIS in Portsmouth, NH

Originally Posted by gsg270

Mik, I've just started gluing the framing on my GIS bulkheads and transom. Do you think its Ok to use a polyurethane adhesive for this? I've just struggled with BH1 using epoxy and know the polyurethane would be easier if suitable.

Thanks, Gordon

Hi Gordon

PU glues need very tight joints to give the required strength. PU has no gap-filling quality and there are likly to be gaps in the bulkheads somewhere. The open time is generally also shorter with PU than with epoxy which can be controlled better with various hardeners to suit the job at hand. So unless you have perfect joints in your bulkheads, you're generally better off with poxy.

Where you have a really good fit the Polyurethane will be fine if you use enough clamps.

So I have little worry about glueing framing flat to plywood. Even some of the mast laminations (clamps might be a problem there) or the rudderbox or the foil laminations can also use the PU.

But where the fit starts to be doubtful in terms of less than perfect fits or difficulty of getting enough clamping pressure I would drop back to epoxy.

The puddle duckers have found that PL Premium is pretty good, but any of the others that are reputed to be waterproof would be fine too.

Best wishes
MIK

Thanks Bruce and Mik for your advice. I've already used the PU for my rudder and will also use it for the centreboard. I think my frustration with the epoxy on BH1 today could have had something to do with the 32 degrees we suffered at about 2:00pm! I'll carry on with the epoxy on the rest of the bulkheads, but carefully choose my time of day!
Thanks again, Gordon

With the temperatures already that high it would save a lot of bother to get the slooow hardener. Putting only the hardener in the fridge also helps. Some people also place their container with the mixed epoxy in some iced water to prolong the working time. I've never tried it but it sounds like a reasonable thing to do.

Originally Posted by woodeneye

With the temperatures already that high it would save a lot of bother to get the slooow hardener.

I was wondering about my hardener. I bought epoxy and hardener in the UK last year and shipped it over with the rest of my belongings. Intending to use it in the cold old UK, I got West 205 which is their standard type. I'll take your advice and get myself off to the chandlers for some of the slow stuff, which seems to be their 206. In the meantime, I'll give your other fridge and iced water tricks a go.
Thanks, Gordon

Originally Posted by gsg270

I was wondering about my hardener. I bought epoxy and hardener in the UK last year and shipped it over with the rest of my belongings. Intending to use it in the cold old UK, I got West 205 which is their standard type. I'll take your advice and get myself off to the chandlers for some of the slow stuff, which seems to be their 206. In the meantime, I'll give your other fridge and iced water tricks a go.
Thanks, Gordon

Yes, that's the one, R105 with H206. Going on the temps you guys are experiencing, maybe even the H209. http://www.westsystem.com.au/files/p...r105_epoxy.pdf

Thanks for the informative link Bruce. I didn't even know the 209 existed. Could be the way to go this summer.

Also mix in wider vessels - the deeper the 'pox the greater the heat it generates in the pot, so the faster it sets. If you mix it in a pot that means the 'pox is shallower, it won't generate the same heat and will give you a longer pot life.

Howdy,

I haven't used the 209, but I have used the fast bote cote in high temperatures.

There is not the difference between hardener speeds that people think, but sometimes it is nice to have the few extra minutes.

The main thing is the handling method. If you leave the fast stuff in a tin then it will go off like a rocket, but if you mix and then get it out on the surface then the heat can escape and you have much more working time whatever the "speed" of the hardener.

So use a snap lock bag for spreading glue mix, or a planned pour over the glass and use a sqeegee to roughly spread the epoxy before tidying it all up.

I would never chill the epoxy as it makes it too hard to handle and will waste time.

Also try smaller batches first and as you gain confidence make the batches bigger.

MIK

Originally Posted by woodeneye

Yes, that's the one, R105 with H206. Going on the temps you guys are experiencing, maybe even the H209. http://www.westsystem.com.au/files/p...r105_epoxy.pdf

On Sunday it was 42deg here and I used the 206 hardener outside while working on our deck without any problems. Working time was a good 30 minutes.

So after quite a long hiatus for the winter and spring, we finally got back to work on our GIS a few weeks ago. We finished planing the 4-sided tapers on the spars, then 8- and 16-sided them and sanded them round. We finished tapering the mast so that it would fit into the mast partner and the mast step after it finished, and glassed the bottom 1200mm. We also taped the top of the mast and both ends of both spars with 2" tape.





We flipped the hull over, cut the the centercase slot, and glassed the bottom with 3oz cloth, then gave the rest of the bottom 3 coats of epoxy. After a few coats we remembered that we had forgotten to tape the edges of the transom, so we sanded them down, put the fiberglass tape on and coated the corners with several more coats.





We took the centerboard to a lumberyard and had it thickness planed to 22mm, and shaped both foils using the foil jig, which ended up going much more smoothly than we expected.



After shaping the foils, we glassed the tips of both, then applied to layers of cloth to the centerboard and one to the rudder.

[IMG]http://farm5.static.flickr.com/4076/4829287230_313a91281e_b.jpg[\IMG]

[IMG]http://farm5.static.flickr.com/4122/4828678293_382ffe48ac.jpg[\IMG]

Most recently, we cut the hole in the transom for the tiller. Although the plans specify a 49mm tall hole with 49mm radius ends, we used a 2" hole saw (51mm) for the ends of the hole, then cut out the middle with a small Japanese hand saw.





If you are more interested there are more pictures on my Flickr page (Goat Island Skiff - a set on Flickr).

Looking good man! Nice to see the progress, I checked out your flickr page a few weeks to see what was going on. I'm glad you're back at it. When it's done maybe we can go for 2-goat sail?

We're hoping to have it finished up and in the water by Labor Day so a 2-Goat sail sometime this fall would be great.

Would be great to have some pics!

Another historic occasion!

MIK