Spruce planked refinish questions

Hello-
new to this site. I have a spruce planked 13.5' flat bottomed, v shaped boat that was originally finished with oakum under life caulk (as best as I can tell), then was epoxy painted (?) with no glass, then enamel painted. Galvenized screw fastners.
I have spent the weekend torch scraping to bare wood (with some goo still their) and belt sanding next.

I am unsure why their is Oakum under life caulk.
Can I just use life caulk and skip the oakum (biggest gap's is @3/16") ?

Can you use epoxy with no glass to get a low maint clear fiinish (is their such a thing)
Maybe just a enamal boat finish is best
Boat has a Johnson 6 and is trailer, only inwater with use- so can't be left too long to expand to seal -if ya get my drift
(a bit wordy for a first post ??)

 

Hi Garvey guy

Also new to site - thought I'd do something useful with it one 1st visit.

I worked for International paint/Interlux as tech service rep. Now work as paint foreman for yacht painting co. My advice is as follows:-

I suspect that the previous owner used oakum to help fill gap but also to build in a bit more rigidity to joint. If it flexes too much it just squeezes all the sealant out and it cracks the paint.

It is ok to epoxy without glass. In fact given construction I'd suggest it. If you glass it, even with thin cloth (200-300gsm) it will stiffen it up too much and the seams will split open I suspect. I know of guys who have glassed OVER the sealant and accept the post cure and visual appearance of the seams but that was on big wood strip/plank boats that had stiff construction.

If you epoxy the hull, you MUST varnish as epoxy is not UV stable. It will go cloudy/milky and overtime crack.

The epoxy will act as water repellent and help prevent rot. I'd only apply a couple of coats. 1 thinned then the 2nd as soon as that has dried enough so the solvent is gone but not so long as it feels cured/hard.

Alternatively thin the epoxy in warm water (IN not WITH ) or use hot air gun after you apply. The thinner the epoxy, the more penetration you will get. The more penetration, the more water resistance.

If you do varnish it, make sure you wash off amine blush thoroughly with wet and dry sanding and plenty of soapy water. Rinse well.

I prefer to apply 1 coat of 2 pack varnish to epoxy. It has less problems. Then go with 1 pack. (adhesion of 2 pack to epoxy is good. 1 pack to epoxy can be iffy. Even after sanding.)

Best of luck. Don't worry. You've done the hard bit! Happy painting/sailing

 

It would be truly unwise to coat a traditionally planked craft with epoxy. No It will not keep out the moisture. This is only possible with encapsulation and then only if the coating is religiously maintained when breached. A vessel that has a coating applied isn't encapsulated, therefore the coating is being used as an abrasion barrier or primer/sealer. As a primer/sealer it does a good job, though it's pretty expensive way to do things.

Testing has shown that the amount of penetration into raw wood has little effect on the ability of a coated substrate to absorb moisture. If you have an 1/4" of penetration or a 1/50" you'll get the same level of protection, in regard to moisture ingress. A solid coating of plastic is a solid coating of plastic. It doesn't matter how thick or deep, unless you are interested in something other than sealing. In fact most standard formula epoxies perform poorly without a reinforcement in the matrix, in all the columns we use to grade it's performance. Now the formulations of epoxy that are intended to penetrate (CPES, etc.) are a different story. These are not near as hard as the standard formulas and can tolerate the movement of the wood, be this from moisture content changes or working under load.

Oakum is a better choice then the usual cotton and is recommended by those that know the difference. It's pounded differently (lightly) as it's fibers can crush if pounded incorrectly.

Adding 'glass to the epoxy overcoat will hasten the rot process, not curb it. Moisture WILL get in, you can rest assured on this truism. It's a fact of the marine environment. Only very well planed repairs or new construction can limit this with epoxy. General repairs, like yours, will not provide the protection necessary, so plan on the movement from moisture content changes. This means the lumber will shake off a hard coating pretty quickly and breaches will permit water in under the coating, where it will have limited avenues of escape, promoting and accelerating rot.

I agree with Mastcolin's suggestion of a UV inhibiting finish coating (varnish/paint) because he's right, epoxy doesn't like the sun much. Didn't mean to step on the new guy's toes (sorry Mastcolin) but the worst thing you can do to traditionally constructed structures is to lather them up with epoxy and or cloth. These structures NEED to move. It's the nature of the way they are designed. If they don't, they'll find a way or things will break, most of the time it's the coatings, but if the coatings/sheathings are heavy or thick, then it's the structure that will give.

 

thanks both- I just posted pic's under wooden boat restoration if interested (I'd do here but I am on snail dial up) I think I'll do standard seal and paint or varnish - The prior owner (?builder) tried epoxyed, then painted over latter (not sure why) and bond was poor and blistering developed. She was tight and no leaks once in water at beginning of season a bit.