laminating frames

[derwent]

I'm in the midst of restoring a 36ft Fyfe designed yacht (1918,Tasmania) . My shipwright friend suggests that I use laminated frames of celery top pine , with intermediate ribs of spotted gum (steam bent ). My question to you good folk is this .Does it matter what I use as an adhesive for the laminated frames ? ie; is there a need for flexibility or rigidity? Is resorcinol better than epoxy or is there something better on the market for this application ? Or can I rely on just the fasteners - plank to frame , and a good coat of varnish/paint ? I do look forward to your replies .
Cheers, Brendan .

 

[Peterduck]

I would definitely opt for epoxy resin to glue your laminated frames. Resorcinol is fine if yiou can get the very high clamping pressures and perfect joinery that it requires. Epoxy is much more tolerant of imperfections. Any flexibility that you need will come from the timber, don't worry about the need for flexibility in the glue. I agree with his choice of timbers.
Peter.

 

[derwent]

Thanks Peter , Dave Golding (shipwright -dave@davesboatshed.com ),also suggested epoxy as an adhesive for laminated frames . But after reading Larry Pardy's book (details of classic boat construction) I thought I'd get some more advice before gluing up expensive and rare timbers . Larry Pardy didn't seem to be a great fan of epoxy products . That aside, I certainly appreciate your response .
Cheers , Brendan .

 

[jon]

I agree with Peterduck, even with excellent joints and clamping conditions in my own experiments I have found epoxy properly mixed and applied is far stronger. I would however always use resorcinols where the joint will be exposed to sunlight and not over coated with an ultraviolet screening and waterproofing finish, also where the joint is particularly important such as scarfs on bends, spars etc.

 

[derwent]

Jon , good to hear your thoughts , especially the bit about spars as I'm intending to construct mast / spars using the hollow birdsmouth method (preferred timber being Hoop Pine) ,so resorcinol's the go ?
Cheers , Brendan .

 

[jon]

I would use resoucinols for your mast, but read the blurb as most are not suitable for curing in temperatures below 50 degrees F. Also at higher temperatures you have to work fast as they dry out before curing. Around 60 degrees works well. Post a pic. of the finished mast !

 

[derwent]

Jon, at the moment the temperature is 22 deg c early evening - late spring . Come summer expecting high 30's -low to mid 40's c . should be right for curing temperatures , human error probably my main cocern, oops, concern . As for pics ,no worries ,but you'll have to be patient .Due to work commitments restoration is postponed for at least a year, on the positive side it gives me plenty of time to chase up some of the rarer timbers I need , ie: huon pine , celery top pine etc. Cheers Brendan

 

[jon]

Looking at the open assembly period times for the Wessex Resins Resorcinol we use here, you would be struggling with the warmer summer temps you have!
At 20'C 15 mins 25'C 10mins 30'C 5mins
So winter would be best but not below 10'C !

 

[keelbolts]

I, also, think epoxy will do fine. There was some concern about laminating white oak with epoxy, but I see that West System Epoxies now offers a special, more flexible, epoxy for that, and similar, purposes. I'd go w/ epoxy for your job. It's been done by a lot of people for a long time now and seems to work just fine.

 

[jon]

Although epoxies are excellent for most applications, I would be very cautious using them for spars. I have seen and heard of quite a few failures, they may failed due to poor workmanship and conditions of course. Perhaps there are some first hand experiences out there ?

 

[derwent]

I am leaning towards recorcinol above the water line and epoxy for the frames if my carpentry skills aren't up to scratch . Regarding spars , I was on Acrospire last year where I first met Dave Golding , the shipwright involved in her restoration . He mentioned that all her spars/mast were hollow and bonded with epoxy ,although relatively new they looked very impressive .Thanks for your input , much appreciated .Cheers , Brendan .