A sticky question

[Michael Rogers]

I am about to laminate some strips of Douglas fir to make up two spars - a yard and a boom, both  8 1/2 ft long. Prime considerations are lightness and stiffness. The question is what glue to use, and whether the ultimate strength and stiffness are contributed to by the glue itself. Has anyone any views or experience?

Partly as a trial run, I laminated up four shorter strips (in a jig because a slight curve was needed) to make a support beam for the dagger board case in my T12. (I won't go into detail, but I decided to use the wood supplied in the kit for this purpose for a slight modification to the boat as supplied.) I used epoxy, and the result was extremely stiff - rigid in fact. How much of that result was down to the wood, and how much to the epoxy itself?

Alternative glues to use for the spars would be Balcotan Regular (I have an unused bottle), or Balcotan's successor Collano Semparoc 60 (apparently Balcotan isn't available any more). They would be a lot easier to use than epoxy, and much cheaper, if they would do the job.

In passing, I have used far more epoxy than was supplied with the kit, and will probably need to get still more - and it ain't cheap! What with epoxy coating everything to start with, some glass cloth-ing followed by the recommended 3 wet-on-wet coats of resin coming up later, and final fairing, one fairly gets through the stuff. Also getting a good squeeze from a joint is inherently wasteful, and I have (temporarily) run out of holes to fill with the  cleaning-up left-overs. I've become canny about the amounts I mix, but it all adds up. That's why using an alternative for my laminating would be preferable if it will do the job, which is a 'squeezing-out-excess-glue' situation with a vengeance. I hope my epoxy economy (or lack of it) experiences are not just me !?

[Julian Swindell]

On the little dinghy I built this summer, the material costs were interesting. The most expensive part was the epoxy resin. I think I used about £75 worth. Next most expensive was the paint. That amounted to about £35. Only then the two sheets of plywood, which came out around £30, although I was not using marine grade which would have been more. In theory I should have encapsulated the whole thing in epoxy but firstly, I couldn't afford to, secondly Iain Oughtred says not to and thirdly, I just wanted to get it finished. Time will tell if I will come to regret it.

You do get more careful with the amount of epoxy you use as a build progresses. initially I was building corners out of almost solid epoxy, but in the end I was being quite mean.

[Clem Freeman]

Its not just you. I have just about used the 3 packs supplied with the kit and am trying to summon up the courage to buy another but at over £100 a go as you say its not cheap.

[Anthony Huggett]

Clem,
     You have it easy on the S17! The BR17 is glass-laminated inside and out, and the underside of the floor. I've just bought my second C-pack (barrel). They are upwards of £250 + VAT.

Anthony

[Clem Freeman]

Clem,
     You have it easy on the S17! The BR17 is glass-laminated inside and out, and the underside of the floor. I've just bought my second C-pack (barrel). They are upwards of £250 + VAT.

Anthony

Anthony,

Where do you get your epoxy from? I haven't seen the C pack below £350 inc VAT.

[Anthony Huggett]

Matt offered me a deal, because the amount of glue necessary (as opposed to what is typically used) for a BR17 is uncertain; Steve and I are the first two kit builds. But upwards of £250 + VAT is still over £300, so it's not cheap.

My guess is that 2 C packs will just about be enough for me - but using Andrew Denman's techniques for making it runnier with mild applied heat might mean a professional could use less. But I'm on the "more is better" theory.

Does anyone else have the recurring nightmare of launching your pride and joy after a year or two's hard work and the glue not having stuck properly?

[Clem Freeman]

Yes

[Michael Rogers]

Anthony

Literal nightmares one just has to live with. However, if you were being metaphorical, I think you have to be pretty slapdash or careless with epoxy for it to come apart. Conversely, if you have done all the basics (clean surface, coat of clear first - unless pre-coated -, getting a reasonable squeeze etc), which I'm sure you have, then relax and enjoy anticipating launch day.

As a complete epoxy greenhorn, I built my Storm Petrel between Dec 2003 and March 2004 (fairing and painting took another 3 months!), through some pretty cold weather. I faffed around with polythene 'tents' inside the garage, thermometers and heaters, and like you was apprehensive about the results and possible disasters. I've had absolutely no problems of any kind, the whole boat feels wonderfully 'intact' and strong and rigid. I trust and expect my T12 to be the same. And I can tell you, the feeling of worthwhile achievement is well worth it all.

Michael