Stabilizing wood during construction

[dmede]

Like many people around here I take considerably longer to build a small wood boat than a professional. Because of that, I’m wondering if I should prime or pre-coat my stem and transom to stabilize them while on the building jig? If so, what should I use? I’m leaning towards a 50/50 mix of basic varnish and BLO.

The other reason I want to pre-coat is to pretect the wood I want bright from all the paint, epoxy and assorted other goops that may get on them during construction.

dave

[bott]

I would stick to the old-tried-and-ture boat sauce:

50/50 BLO/Terps + a splash o' pine tar to taste.

apply hot out of a old crock-pot if possible.

[dmede]

What I'm asking about is just an under coat to protect and stabilize the wood during a year long build. Some of this will be painted over with marine grade enamel or varnish (or boat soup, not decided on how to do the bright areas yet).

[Thorne]

Not to start a firestorm of controversy, but some of the pieces might be well protected with one or two coats of CPES, particularly those which will be finished bright and won't be exposed to the sun during your storage or building process.

I used both BLO/Turps and Smith's CPES on various parts of my dory to be finished bright, and the CPES gives a very nice glossy basecoat/primer that takes varnish (with the necessary UV protection) well. It also took the marine enamel very well, and some others on this forum have indicated that it works well under either varnish or paint.

[dmede]

Thorne, good idea, but I think I'll pass on it for various reasons. One is, I already have everything I need to coat with BLO or BLO & VAR, no need to go out and buy something new. The other thing I'm struggling with is whether or not I will use an oil only "boat soup" inside or an Oil/Varnish mix (my prefernce right now). I will most likely not be straight varnishing the inside.

My main question is, is it at all a bad idea to start putting a finish on some of these peices before planking up? If I do, do I need to watch out for areas that will receive bedding?

[Jay Greer]

A lot of us old geezers often use red lead on frames, keel timbers and floors as well, if the boat is being built outside.
Choosing what paint you will use and priming things will help. Or, if frames are to be varnished a coat can be put on just to keep the wood clean can be done.
The most effective way to protect the wood is to build in an unheated building. This allows the wood to normalise slowly to changes in humidity.
None of my shops have ever been heated. The office and small tooling rooms are kept comfortable with wood burning stoves.
But the main shop has no heat.
JG

[djswan]

I use Benite by Daly's as a pretreatment.

[Boatmik]

Hi All,

If you are building outdoors or with green timber or really big sections of timber it might be worthwhile.

But apart from this I've never seen bits move much on a jig unless it was poor quality.

The other aspect is that everyone is going ahead as explaining their favourites without finding out how the boat will be finished and what construction method is being used.

If sealing is necessary for some reason then it needs to be compatible with all the products to follow.

If going ahead to produce a fully epoxy sealed boat I fully precoat bits wet-on-wet with the full three required coats before they go in making sure that most areas that are to be glued to later are masked off so that they present clean wood to following gluing.

But this is as a form of labour saving rather than from any necessity to prevent timber from moving.

Have a look about half way down this page.
http://members.ozemail.com.au/~storerm/Faq/Avoidingamine.html

Best Regards
Michael Storer

[Ken Hutchins]

A coat or 2 of thinned varnish will slow the drying and help prevent movement and splitting. Get the varnish on immediately and again after any cutting of the wood.

[erster]

Even after just the rough sanding, I seal my woods with thinned varnish with turpentine. You can also use a bit more penetrol than you would do so in flow control in painting, and it will flatten a bit, cutting the finish so that sanding uniform is easier when you do get back to it. I also use Miniwax Helmsman, semi gloss, on occasions, even for suttle woodwork finishes, in lieu of high gloss. Its a bit cheaper than z-spar, in the buildup process, and is thinner for soaking in the grains. Two coats works fine, back to back and can be worked around during your lengthy process and is easily removed whe ready, if soiled, keeping any dirt out of the wood, deeper into the grains. This really stabilizes the woods, especially any resawn parts.



This also allows for seeing any areas that have not been truely sanded smoothly. In lighter woods, you may miss some power tool swirls thats not always apparent when unfiinished. Wiping down with denactured Alcohol, works along the way, during this job of prep work.


http://img.photobucket.com/albums/v356/Bateau1/23sealercoatbow.jpg