Boatbuilding Materials for Kids
Many traditional boatbuilding materials are toxic or
involve some element of risk with skin contact or if breathed.
However, there are safe alternatives for boatbuilding with children.
- Polyurethanes: Gorilla Glue is the best, most solvent-free of several brands.
- Urea-formaldehydes: (Weldwood). Long boatbuilding history. Comes as a powder to
be mixed with water. The powder can poof up when mixing - don't let kids breathe the powder!
Formaldehyde sensitive individuals take note. And yes, the label says that the state of California
has determined that formaldehyde exposure causes cancer. However, I think we are talking
very low concentrations here, and minimal risk in my opinion.
- Titebond II: If reliable, would probably be the best alternative by far! Experiments in progress...
Bedding Compounds and Thick Adhesives
- PL-Premium Polyurethane Construction Adhesive: cheap, cures in wet and cold,
great adhesion, very low emission of volatiles, appears quite safe.
Primers: Its hard to beat good old-fashioned shellac primers (e.g. Zinsser B-I-N) for low toxicity.
Shellac is approved as an edible substance, used for candy gloss and
oral pharmaceutical coatings. Shellac has a
fascinating and ancient history:
it's a resin produced by a scale insect and scraped off of trees in India and southeast Asia.
Chemically, the shellac resin is laccaic acid
(C26H19NO12 and variants).
You probably don't want to eat the titanium dioxide pigment added to white shellac primers,
but still I think shellac primers are the way to go with kids.
Shellac is dissolved in ethyl alcohol, which comes off quickly: dry to recoat in 45 min!
No other harmful vapors or solvents.
Shellac adheres well to glossy surfaces like epoxy, and makes a good base for bonding topcoats.
I've had very good results with white shellac primers on large, traditional boats
top coated with marine oil-based paints (I usually use International brand).
Shellac primers are supposed work well with latex paints also (but NOT polyurethanes!).
Steve Anderson had this to report about a Gougeon Brothers test of various primers over epoxy:
Okay - I found the West System test results
A top score on their tests was a 5 and the following primers received a
score of 5 in all catagories:
The following primers tested scored some 5's in some categories but in other
categories scores ranged as low as 0:
- Kover - Stain by Zinsser ( oil)
- Bulls Eye 1-2-3 Primer sealer by Zinsser (Note: acrylic latex, NOT B-I-N)
- ProBlock by Sherwin Williams ( latex)
- Flash Bond 400 white - by X-I-M ( solvent based)
- Latex Exterior Primer - Benjamin Moore ( latex)
- Weather King II Exterior Primer - Fuller O'Brian ( latex)
All of the latex primers did well - they did not test Kilz II.
- Moorwhite Alkyd EXT.Primer - Benjamin Moore ( alkyd) Scores ranged from 5 to 0
- Ext. Wood and Masonry Primer - Fuller O'Brian ( alkyd) scores ranged from 5 to 0
- A-100 Exterior Primer - sherwin Williams ( alkyd) scores ranged from 5 to 0
I used Kilz II on the interior - and did have some problems with it peeling
in places that I didn't sand as thoroughly. I called the Kilz people and
they were horrified that I was using it over epoxy - and even more horrified
that I was using it on a boat. They did say however that their own tests indicated
that it was not real good to use over epoxy.
About Kilz, Steve Heil reports:
Kilz (the original) is the only stuff I've used. This stuff really
smells bad and if yuo're not careful it can make you dizzy when using
it in closed spaces. I think the reason for this is because the
volatiles flash-off very quickly. This stuff dries very fast (less than
30 minutes). I have used it on many outdoor and indoor project (however
not a boat) and I've never had any problems with it adhereing to
anything nor has any top coats failed to stick to it.
With any of these, rough up the epoxy, and make sure the epoxy blush is removed first!
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