tar as leveler

Frosty....

Well...... it's never that easy with boats. Below are pictures of my boat under construction.....no frame pockets but rather double sawn yellow cedar about 4" by 7" at the heel where they meet the keel, frames are spaced 14" so there's 10" open between them...note the depth of the spaces between the frames aft, some of those pockets I can just barely reach the bottom of......holes at the bottom would be totally inaccessible and were would they drain to? Drainage direction changes with trim.......

 

A few years ago we did some reframing on a 55ft 3 masted schooner which was built in Florida in the 1950s,they had used what i suspect was pitch,poured in while molten which then leveled off and set up rock hard, a very bad idea as it apparently shrunk on cooling and water was able to go under it, recent owners had used roofing tar to replace some of it,an equally bad idea as it tended to melt somewhat as refered to by the OP,it then proceded to plug the bilge pumps, what a mess, i dont know what the answer is but neither of these is it. I have encountered the same issue with the pitch on a Luders yawl which was built in Japan at the end of WW2. I like the idea in principal of pouring in a liquid which sets up level but i cant think of what would be a material which would actually work.
Steve.

 

Tad mentioned cement and there are self levelling compounds used in the flooring business. Here is a link for a product used in the UK.

http://www.wickes.co.uk/latex-floor-levelling-compound/invt/224669/?source=123_74

Use one bag and experiment would be my suggestion, however I would trial only one bay between two frames and set a couple of lifting hooks into the wet compound, so as to test whether there is a satisfactory bond between timbers and hardened compound. If so, I would also seal the surface of the compound with glass cloth and epoxy resin.

Best of luck.

 

Me, i dont build with traditional construction methods so this is not an issue for me, with more modern forms of construction i prefer decent sized limber holes and usually epoxy in pieces of G10 or pvc tube rather than just trying to seal the end grain of the holes. However, with planked boats where they often used to use pitch as a leveler i think to be sucessful perhaps trowling on a thick layer of something gooey and then pouring the cement over that to fill the void may work, i suspect that cement alone would be too rigid and allow moisture to get between it and the wood and cause more problems than it would solve, most of the roofing tars ive used are too thin,im thinking of something more like toilet bowl ring consistency,you could warm it up to spread it, at least it would provide a resilient interface that would keep moisture out. I dont know if it would work or not but what i do know is that on the few boats ive worked on with pitch or roofing tar as a leveller it flat out didnt work.
Steve.

 

The product used was a foundation coating. I cannot be more specific because I didn't get a copy of the invoice. I liked the idea of trying to replicate what Jesperson did in building the boat. But Jesperson wasn't doing the repair work, nor anyone so conscientious. Whether it works as intended remains to be seen. Meantime I've something of a mess to contend with. I would not try this again. My trust in the guy doing the work was misplaced.

 

Polyurea might offer a choice. Again it's a UK link, but search your local supplier.

http://www.polyureacoatingsuk.co.uk/polyurea-coatings-applications/roofing.php

 

That polyurea might work,it does bond well,ive only seen it sprayed as a coating but maybe it would work poured. I had the front of my westfalia camper, masked it off to look like a bra, its been on for 2 years and looks like a sucess so far.
Steve.

 

I've done some industry testing with these types of polyurethane coatings and they work well if the film thickness isn't excessive. This is a relative term with these coatings, as they generally are fairly thick, but ideal film thicknesses for these is 30 to 50 mils. The more you go over this amount the bigger the shrinkage issue becomes.