Epoxy, Marine Glue and Marine Ply

Experiencing a moment of hankering after a wooden boat again, The Paradox Micro Cruiser might be a sensible approach given that it is only 14 foot of wooden trouble.

Trouble might be an unfair description to a wooden boat. Perhaps 14 foot of wooden boat maintenance might be fairer.

Image of a Paradox sailing vessel called Faith

Paradox Faith

I followed the building detailed on Johanna. That whiled away an hour. What struck me as the story rolled, that the author was building, and continuing to build, as other builders launched. We all work at our own rates, and build quality is little respecter of time. The authors finished boat certainly appears to be of a high quality.

What went through my mind was the authors attitude to using ‘the best materials’, that were to include Marine Ply and copious quantities of Epoxy Resin. It just struck me for what is a 14 foot boat that isn’t left on a mooring but trailed to her launch site, its a bit of an overkill. Indeed on this site now only available on the WayBackMachine [the Internet Archive site] the builder lists the following building costs:

When building my Paradox I used only the best materials, including high quality plywood and bronze fittings for the rudder. The table below does not account for hidden or incidental costs such as those incurred by using the car for frequent visits to suppliers of materials, telephone calls and correspondence.

Item

UK £

Timber

996.92

Plywood

400.00

Epoxy, Hardener, Filleting and Fairing Blend

575.97

Chandlery, Paint and Rope

738.70

Woven Roving (Fibreglass cloth)

105.45

Nails and Bronze Fittings

285.49

Polycarbonate

123.83

Anchors and Chain

024.99

Nuts and Bolts

029.80

Sail (Secondhand including import duty from US)

188.35

Lead

070.00

Other Items, including Depth Sounder (Secondhand)

270.88

Boat Total

3810.38

Other Costs

Tools and Clamps

099.56

Road Trailer (Secondhand) and Lock

528.99

Tow Ball and fitting to car

176.25

Total

804.80

GRAND TOTAL

4615.18

Reckon on taking about 1000 to 1500 hours for building your Paradox, according to your skill level, tools at your disposal and the quality of finish desired.

So I went on to ask the question “If your not going to use Epoxy Resin as your glue when boat building, what are the alternatives?”

I found this two part empirical testing series where the author is actually choosing his glue and wood through a process of testing. The results were interesting and perhaps shifted the attention off the glue and on to the ply wood. Indeed his interest might be a little more acute than us sailors since his intention is to make a wooden submarine.

Fate throws him a “spanner in the works”, befitting his keen interest in breaking strains of materials as shown in the third video.

YouTube Preview Image YouTube Preview Image YouTube Preview Image

The consideration of glues is far from trivial since it would be a real pity, but not the first time, that a boat has been launched where the proud owner/ builder is soon to find out that his preferred glue is not as waterproof as he thought it was.

While an initial saving on the cost of adhesive and glues may be attractive, the costs further down the line can far outweigh the smiles of the initial savings. Gorilla Glue is claimed by the manufacturers to be waterproof, while Wiklpedia has other ideas and has more to say here. Perhaps Epoxy it is after all.

But what did they use before this? Resorcinol-formaldehyde resin glue?

That your Marine Grade Plywood is ‘boiling water proof’ it certainly isn’t laminated together using Epoxy Resin. So there is an alternative and Resorcinol-formaldehyde resin glue fits the bill. Taking the other versatile handling / thickening agents and gap filling properties of Epoxy into account, Epoxy regrettably comes out ahead. A shame really, just cause its just so expensive.

As our author/ builder above costs out for his Paradox, Faith, the Epoxy and sundry materials cost more than the carcase of the boat. In other words its costing more to stick the thing together than it is for the base materials to build it. I guess as boat people say, that’s boats for you.

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