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five guys named moe
01-25-2010, 08:55 PM
I bought a sweet little flat bottom skiff last fall and got some good advice here before the purchase... thanks all. I'm now working on repainting the boat and doing a few repairs and all has been going pretty smoothly up until now... Her paint was peeling pretty badly around the rubrails and gunwale, so I stripped that and in the process decided I would strip the hull as well because the bottom paint was flaking off in spots and generally pretty ugly. In retrospect, maybe I should have left the bottom as is. I used a paint stripper called Aquastrip to get the antifouling off the bottom which was expensive, but worked really well. It's sort of a gel that gets applied and then strips off very clean. Initially, I was a bit worried about the stripper and residue getting in the gaps between the planks and not being able to clean the seams afterwards, but just decided to move forward figuring I could scrape it out with a putty knife it needed. In retrospect, maybe this was a bad plan and I should have just hosed it off and used a brush on the seams or something. The bottom has has dried out quite a bit since it has been in the garage, so there were gaps of maybe 1/16" between the longer planks at the aft. The forward planks have not spread as much. I stripped the paint last weekend, but didn't get around to looking at the seams until yesterday. When poked around with a thin putty knife, I found some brown bedding compound between the planks which looks very similar to the bedding compound used around the rest of the boat (bedding planks to transom, etc). Its sort of a clay type consistency - very soft in some places but more like a hard sealant in others. Anyway, before I realized that it might actually be bedding compound and not some mixture of stripper and old bottom paint my newbie curiosity got the best of me and I poked around with the putty knife enough that i'm a bit worried I might have spoiled whatever is in the seam. I don't recall seeing anything between the planks before, but it was under quite a few layers of old bottom paint, so it was hard to tell.

So, to finally wrap things up... any thoughts on how I should move foward? There are two or three seams that I messed around with so I know I didn't screw up the entire boat, but... Do I reef out what's there and put something new in? Do i leave it as is? When I used her last fall, she leaked a bit after I launched her, then stopped after maybe an hour or so, which I felt was pretty reasonable. A few photos are included. Also - any ideas on what she's planked with? The guy I bought it from said oak, but it doesn't look like oak to me - more like cedar?
http://lh3.ggpht.com/_72BOfBlYI7E/S15D3kIW8mI/AAAAAAAAAJk/GX2NQWigpZ0/s720/P1251225.JPG
http://lh4.ggpht.com/_72BOfBlYI7E/S15D4r3rIPI/AAAAAAAAAKY/G0IiIAjNMWI/s512/P1251231.JPG

Thorne
01-25-2010, 09:30 PM
Those seams look plenty tight to me, and I suspect they'll swell up right away when the boat gets in the water. Also your primer and paint will fill them to a certain degree.

Otherwise I've seen a lot of recommendations here for thin bits of cotton pushed into the seams, painted with red lead if you have it, then painted over. There is also a good selection of commercial seam compound available, but I really think these won't need that level of material.

Let's see what the more experienced folks say.

Bob Smalser
01-25-2010, 09:32 PM
Doesn't look like you have caulking seams....those planks are just butted together. Is there no cotton in there? Are any of them tapered?

How do you plan to use the boat? If it will live in the water full time you can squirt more soft goop in there, repaint and relaunch. But she will always be a weeper and a seeper in the summer.

If the boat will be drysailed from shore or off a trailer, you'll have to make proper caulking seams if you don't want to waste the time necessary for the planks to swell after launch. Remove them from the boat, plane in caulking seams, add a plank if necessary, and caulk the boat with cotton.

http://pic20.picturetrail.com/VOL12/1104763/2595357/306698154.jpg

If you don't know how to do this, all John Gardner's books and others describe caulking seams in detail. If the planks are nailed rather than screwed, the planks can be pounded off from the inside, pulling the nail heads through the cedar if they don't pull out of the chine, and the resulting holes plugged.

five guys named moe
01-25-2010, 09:47 PM
Thanks guys. There aren't any caulking seams. I thought they were just butted together without anything in between which is why this caught me off guard.

I don't know what I plan to do with the boat. She will probably stay in the water a few weeks in the summer, but I will probably launch her occasionally to go fishing and just wet it down before I head out.

Bob Smalser
01-25-2010, 10:01 PM
I don't know what I plan to do with the boat. She will probably stay in the water a few weeks in the summer, but I will probably launch her occasionally to go fishing and just wet it down before I head out.

From here it looks like the builder knew what he was about when building an inexpensive skiff quickly. Young trees, but all heartwood and the cups are right.

These skiffs often have a tapered plank every 4-6 feet that was trimmed over-long and driven into place to tighten the planks already installed in place of caulking.

If the rest of the skiff looks this good, you'll only be adding 1-2 days to the project to rebuild her with a caulked bottom. And even reusing the same planks, you can outgauge the plank ends for better protection from rocks and add sacrificial wear stringers if she doesn't already have them.

five guys named moe
01-26-2010, 08:40 PM
Thanks Bob. I'm intrigued by your suggestion to caulk the seams. I've spent many hours over the past few months searching the forum trying to learn as much as possible and have noticed you making that suggestion more than once. Some very good information here: http://www.woodenboat.com/forum/showthread.php?t=71002&highlight=cross+plank. You noted that with a caulked bottom, she should be fine being left in the water for a few weeks without any compression set, but theoretically still dry when dry sailed. Am I reading this right? I'm not freaked out by water in the boat, but dry boat sure is nice.

All the planks are in pretty good shape and I would hope I could re-use them. Should I worry about any compression set that has already occurred? The boat was kept in the water summers by the previous owner. The planks are roughy 3/4" and vary in width. I haven't really looked to see if there is a tapered one. She is nailed with what I am assuming are ring nails. If I tap all the planks off from below, should I worry about damaging any of them when I do it? As you can see in the photo, the bottom planks are fastened very well to the side planks AND chine. Would it be advisable to drill off the heads of some of the nails and try to pull them out after the planks come off? Would I even be able to get them out that way?

Lots of questions. Thanks for your help.

orbb
01-26-2010, 09:06 PM
If you are pulling all the planks off, why not double plank with thinner stock, offsetting the planks? Isn't that recommended for boats that won't live in the water?

Perhaps more work and expense than you want, but it might solve your problem.

Bob Smalser
01-26-2010, 09:47 PM
All the planks are in pretty good shape and I would hope I could re-use them.

Should I worry about any compression set that has already occurred? The boat was kept in the water summers by the previous owner.

The planks are roughly 3/4" and vary in width.

She is nailed with what I am assuming are ring nails. If I tap all the planks off from below, should I worry about damaging any of them when I do it?



If the planks are in as good shape as the ones shown, of course you should reuse them. The only reason I mention adding a plank is that over the length of the boat you'll lose a couple inches cleaning up edges and planing in caulking seams. Add it to the stern so you can "outgauge" most of the reinstalled planks. (Cutting the ends square instead of flush with the side so they protrude a bit. They make a natural bumper protecting the sides and chines for when you bang a submerged rock.)

If the wood is Western Red Cedar....and it looks like it from here....there is no real reason to double plank, as even flatsawn is sufficiently stable for however you want to use the boat (providing you caulk it). If in a few years you do develop a weeping plank, (usually where the stern rides out of the water baking in the sun until the boat is loaded), you can worry about it then and double plank just that section during the next rebuild another decade down the road.

Don't try to pull the nails. You can pry or pound the bottom loose a tad, then slip a Sawzall blade between plank and chine/side, cut them off, and if bronze, drive the stubs flush. The heads remaining in the planks can be driven out using a punch, and the holes repaired with epoxy thickened with wood flour or cabosil.

If the nails are bronze, often the easiest removal method is to pound the planks completely off from beneath with a 3lb hammer and a short length of 2X6 for padding. The heads will fold and pull through the plank, and the resulting holes repaired afterward. The nails can be cut off flush using nippers and the tips left in the wood.

Last, remember while the plank end-chine joint doesn't get a planed caulking seam, laying a strand or two of wicking (pure cotton string) in the bedding where plank ends lay with the chines will go a long way to insure a seep never develops there from planks cupping a tad. And when the planks are reinstalled, they are (each in turn) pulled into the planks already installed using serious door clamps to insure they are as tight as they can be before nailing.

five guys named moe
01-27-2010, 10:50 PM
Thanks for all the help. I looked today and the nails appear to be stainless. Should I still go ahead and cut them and drive the stubs into the chine? Any suggestions on what to refasten her with?

I picked up Gardner's book. I'm assuming you're suggesting a 1/8" beveled caulking seam like he talks about. Anyone have any suggestions for seam compounds here?



Last, remember while the plank end-chine joint doesn't get a planed caulking seam, laying a strand or two of wicking (pure cotton string) in the bedding where plank ends lay with the chines will go a long way to insure a seep never develops there from planks cupping a tad. And when the planks are reinstalled, they are (each in turn) pulled into the planks already installed using serious door clamps to insure they are as tight as they can be before nailing.

Is wicking different than cotton caulking? If so, where can I find it? Any suggestions on what to use for bedding at this joint?

Bob Smalser
01-28-2010, 12:55 AM
1) I looked today and the nails appear to be stainless. Should I still go ahead and cut them and drive the stubs into the chine? Any suggestions on what to refasten her with?

2) I'm assuming you're suggesting a 1/8" beveled caulking seam like he talks about. Anyone have any suggestions for seam compounds here?

3) Is wicking different than cotton caulking? If so, where can I find it? Any suggestions on what to use for bedding at this joint?

1) Yes. And refasten with bronze or SS screws or ringshank nails. Stainless steel won't matter in this boat.

2) Yes. Look up seam compounds at Fisheries Supply....there are several like polysulfide....or you can use common door and window caulk.

3) Yes. And bed the joint with anything that remains soft and nonadhesive like oil-based bedding compounds made for the purpose....Dolphinite or Interlux bedding compound.

Caulking cotton:

http://www.fisheriessupply.com/online/ln_menu/product.asp/mode/1/product_id/9658/Ntt/cotton+wicking/N/0/Dx/mode+matchallpartial/Nty/1/R/31509/D/cotton+wicking/catalog_name/FISCO/Ntx/mode+matchpartial+rel+Inactive/act/A01/Ntk/All

Wicking:

http://www.fisheriessupply.com/online/ln_menu/product.asp/mode/1/product_id/9659/Ntt/wicking/N/0/Dx/mode+matchallpartial/Nty/1/R/31510/D/wicking/catalog_name/FISCO/Ntx/mode+matchpartial+rel+Inactive/act/A01/Ntk/All

Bob Smalser
02-08-2010, 07:56 PM
If the planks are glued on, I'd try using the boat for a season to see how much it seeps and for how long, and whether I can live with it as-is.

But besides adding a double planking layer or sinking the boat after every use, another alternative to stop the seeps if the cross planks have been bedded in 3M 5200 is to rout planking seams in place.

http://pic20.picturetrail.com/VOL12/1104763/2595357/382474393.jpg

A veiner bit in the router or an old Skil saw blade ground at your local sharpening service to the profile of a planking seam will make short work of the task. Clamp or tack on a temporary straight-edge guide to insure your cut remains centered on the seam.

Set the depth to around 2/3 of the plank thickness so the lower third of each pair of abutting planks remain touching, blow out with air, paint with 50-50 linseed and turps, and caulk with cotton. You can buy a proper caulking iron or blunt and taper an old butt chisel on the grinder for that purpose. Follow up with soaking the cotton in red lead or copper bottom paint, when dry fill with seam compound, and paint the bottom.

While not as thorough a job as removing the planks, this will work, and you can postpone dealing with glued-on planks until you actually have to replace one.

five guys named moe
02-09-2010, 01:34 PM
Thanks Bob,

Well, getting the planks off will be a royal pain if they ever have to come off. They are all glued in place at the chines and to the keel. I spent the afternoon cursing whoever built the boat. I cracked one of the planks trying to get it off, then spent the better part of the afternoon with a chisel trying to delicately get the planks away from the chine without breaking anything. Haha... all good fun.

Piginabag
02-09-2010, 10:13 PM
Never trust anyone who claims to be an expert, and don't listen to anyone who wants you to make a good skiff more complicated. I'm an actual professional boatbuilder, and not that it's worth much, but I can tell you what most boatbuilders would do in your situation: 1. Relax. It's OK. The biggest threat to your boat is advice from Big Thinkers. 2. The secret best bedding and best paying compound below the waterline, especially for a cross-planked skiff, is roofing tar. It stays stuck, but squoozes out when she swells. It skins over, you can scrape off the excess, and it's $4 a gallon - or they load it into cartridges for you. Only problem is it bleeds through topsides paint. If it pains you to not purchase a Marine product, Slick Seam is a lovely wax for seams below the waterline. To recap, above all, relax. If it ain't broke don't fix it - or saw it - or rout it - or tear it apart; unless you'd rather rebuild a skiff than use it.