1948 15ft Plywood motor boat Restoration - Sydney, Australia

by Jenny Brand
(Sydney, Australia)

Hello everyone,

I am restoring a 15ft, 1948 plywood motor boat, and would like to know what your thoughts are on what methods to use.

I have previous experience on marine ply Moth's, and fibreglass boats.... but this one is of an 'earlier vintage' and I would really like to carry out the most appropriate and respectable methods to maintain 'her integrity' (hehehe..)

I am currently in the process of stripping back all varnish and topside paintwork to bare ply.

I have found a heat gun is best on varnished areas, and have been using Lemon Peel paint stripper on the topsides.

The topsides will need touching up with the heat gun, then everything will need a sand.

I have plenty of Covid19 time and practical expectations on the timeframe.

So far I have considered:

1) Fibreglassing to the capping rails, to provide more protection and waterproofing. My concerns are:
a. it will take away from a traditional wooden hull, and
b. I am worried that if water penetrates the ply from inside the cockpit it will cause rot.

2) Applying epoxy resin (Bote-Cote, made in Australia) with TPRDA (timber preservative and reactive diluent additive) to the hull, inside and out, so it soaks into the marine ply (a bit) preserving the timber by waterproofing and strengthening.
My concerns are:
a. with all of the internal framework, there is no way I will be able to coat 100% of the hull, which could lead to the ply getting wet in areas and not being able to dry out = rot.

3) What do you think about Copper-Cote from the waterline below, Epoxy topside paint for the topsides (classic white), and Epoxy with a UV coat on deck. I would really really love to stay away from varnish (I know this is a wooden boat forum, and sincerely apologise for an offence this may cause!) :)
THIS IS CURRENTLY MY 1ST PICK!.. after much consideration.

Please.... guide me.

Many thanks,

Comments for 1948 15ft Plywood motor boat Restoration - Sydney, Australia

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Apr 08, 2020
Preserving, Waterproofing & Strengthening
by: Dr Hugo

Hi Jenny,

To waterproof and preserve timber and plywood, I use a mix of epoxy resin diluted (10%-25%) with acetone.

Thinned down, this saturates and penetrates well into all types of woodgrain.

When working, if it becomes a little thick due to heat and evaporation, add a bit more acetone to keep it thin.

You don't need to build up a thick high-gloss finish, but apply 3 coats for best results.

Use a small brush or roller for accessible surfaces.

But for hard-to-get-to crevices, nooks crannies and corners like behind framing etc, rig up a plastic squirt bottle with a small jet to shoot into those areas.

This totally waterproofs all cavities as it soaks in, while the epoxy resin strengthens everything.

The plywood especially becomes "re-marinized." Once dry, lightly sand if need be before applying primer and topcoat.

Hope this helps.

Dr Hugo "Hallelujah"

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