" Question on Gluing the mast"

[Florin {VACATIONER}]

Does anyone have any words of advice regarding the gluing of the bird's mouth spar? We are pretty much ready to go now.

We have epoxy and plastic resin. The epoxy takes a week to fully cure.

Any do's and dont's?

Thanks

Florin

[Frank Hagan]

Because of the length, you'll need two people. I made three "cradles" by cutting a half circle out of plywood with about a 5" diameter, then put feet on them. The cradles helped support the staves. I had them laid out beside the cradles, buttered one side of a stave with epoxy thickened with wood flour, and then put it in the cradle. The next stave would then be buttered, and put in the cradle nesting with the prior one. With a helper to stablize things, it went much easier than when I was trying to do it solo.

You can see one of the cradles in this pic, after the completed (second and successful) mast was removed from them:

My first mast was a failure. I have the gory details on my page on it at http://users2.ev1.net/~fshagan/mastm.htm. I used stainless hose clamps and tightened them up ... really tight! I ended up twisting the staves, and it caused the mast to be bent, or the way I was laying it on the floor (with some of the turnbuckles on the clamps down) caused it to cure bowed. It was one of those "moaning chair" moments!

[Charlie Jones]

a week!!! Boy are you gonna get great penetration

I solved the assembly problem with a ring of 4 inch PVC (for the mast)about an inch and a half wide. Laid all the staves out with the mouths up, coated with resin, then started sticking them into the PVC ring at the big end. That kept every thing in one place while I did the last few staves. Then I used hose clamps like Frank did, but I put all my turn screws on the up side. I did reverse every other one so the screws were pulling from alternate directions. Then I wrapped pieces of bicycle inner tube around in between the clamps and laid the whole thing flat on a floor.. I was aware of Frank's problems so I got down and eyeballed the spars for straightness after they were on the floor- all came out great and is easy to do.

Just don't squeeze too tight- remember - all it has to be with epoxy is held close together - as soon as the clamps started to dent the corners, I stopped.

[Florin {VACATIONER}]

Frank,

Great minds think alike! I've already made those jigs a couple of days ago except the cutouts on mine are not circular but triangular, basically the staves should sit in the "V" cradle. I've made 8 of them so that the mast is supported every about 2' or so. My plan was to mark the centres of the bases of the cradles and then snap a chalk line on the cement floor of the garage. Then, hot melt glue the cradles on the cement lining up the centres with the chalk line. This way the axis of the mast would end up straight. Now I just have to make sure the garage floor is reasonably level if not, I will have to shim the cradles up a smigeon until they are all level. Instead of the radiator hose clamps I was thinking of using plastic wrap-ties in order to avoid overclamping. Do you guys think this would work?

The reason I'm hesitant to use the epoxy is due to the fact that it takes so long to cure. This epoxy was designed especially for making aircraft wooden fuselages, which need great penetration to be strong thus the long cure time. The other downside is that it is kind of runny, so it doesn't have any gap filling properties at all... well kind of. I still have 3qt leftover from my previous aircraft project. I guess I could mix a little sawdust into it to make it thicker to solve this problem. I do have plastic resin glue, so I was kinda hoping I could have this cured overnight so that I can still do work in there next day as opposed to a week later, for I am worried not to bump it while still not cured. Any thoughts on this?

Thanks a lot guys

Florin

[Frank Hagan]

The plastic resin glue will work, but it does dry dark. You'll have a dark line on each stave if your mast wood is light colored.

The wire ties should work fine also ... you don't need a lot of pressure, but do need to keep the staves together and keep them from twisting.

You're well prepared ... probably over-prepared, but better to be that way than do what I did ... and rush around trying to get everything done as the fast setting epoxy is curing!

[Florin {VACATIONER}]

The fir staves are pretty dark and we want to stain it dark red mahogany like the rest of the brightwork so the plastic resin probably won't show almost at all.

Thanks Frank, I guess we may even get it done tonight when I get back from work.

Cheers

Florin

[JTam]

When I made my bird's mouth mast, I rolled up some newspaper into a tube that had the same diameter as the inner diameter of the mast. That way once all the staves had epoxy on them, I could form the mast around the tube. The newspaper tube was only about 12" long, but that was enough to keep the mast from caving in on it's self. I used hose clamps to hold it all together. Once the mast was clamped I removed the tube.

[Chris Gerkin]

I have used epoxy and gorilla glue. The epoxy has tha advantage of a waterproof coating inside the mast. The gorilla glue was easy to use and dried quicker. The hose clamps and stands work great. Once you get a few staves in the rest go pretty well. Just wear rubber gloves. I just bought DF 18 feet long for the mast and it will be a bridsmouth. This will be almost the end of the wood work. Then there will be rigging , sail and other stuff.

On another board I posted that I may sell the boat. I think I have too much time and effort in the boat to do that. I may have found storage and slip space.

[Florin {VACATIONER}]

I know what you mean Chris, the mast will be pretty much the last piece which needs any woodwork (for now). After that its off to glassing, finishing, painting and rigging.

I can almost see the light at the end of the tunnel.

I hope you can keep your boat.

Florin