splining an oak hull

[rients]

After replacing some of the frames on my 1924 35ft double-ender we have come to the outside of the hull. Because of the condition of the seams and the leaking of the hull we want to spline it. The reasons for splining are to get it watertight permanently and to stiffen up the hull.

In the past 80 years a lot of oil has leaked in and through the hull, showing on the outside. Except from the discussion on oak and epoxy, this is another reason not to spline with epoxy. We think we will never get the oil out and get a good bounding.

Therefore we asked around for another strategy. What some restorers came up with is gluing the splines in with Sikaflex. Does anybody have some experience with or advice on this? And… does anybody have some advice on treating the hull afterwards, since epoxy doesn’t seem to be an option,

Thanks and looking forward to your reaction.

For pictures of the boat:

http:// pictures of elisabeth (http://home.planet.nl/~visse421)

[warwick]

I can't help but wonder how you got oil through the planking, however perhaps you may try a test piece with epoxy and see what results you get. Sikaflex whilst it sticks like s#%t to a blanket I have not heard of it being used for this application, I have recently splined a 1962 30' double ender and am now in the process of sheathing the hull with veneers, doubt if this would work on an oil soaked hull tho'.

[rients]

Thanks warwick. Maybe I have to be clearer. The problem is below the waterline and it is a preparation before putting antifouling on. The oil was in the bilge I guess and just soaked the planking around it. The sikaflex (I don't know yet what number, but reading the discussions it's the one that is almost the same as 3M 4200 I think)is used as a glue. The motivation is that the bonding is very good, it is flexible (so the wood is allowed to swell a little, might be necessary because my deck isn't completely watertight)and I won't have to take any risks on the oily parts and the discussion on oak and epoxy in genereal.

[Bob Smalser]

I'd look at cleaning enough oil from the wood for an epoxy bond...testing the gluebond thoroughly before I did the entire boat.

A mineral spirits or turpentine and whiting paste (powdered chalk) applied thick and warm and left to sit over night will draw out even the worst the oil in a couple or three applications. The glue bonds for the wedges will be to freshly-milled surfaces...clean the oil from the planking before milling those surfaces, and I suspect epoxy will work fine.

I know of no goo or glue that penetrates old motor oil very well....the oil has to come out.

If my epoxy test showed I couldn't get a good bond to my cleaned oak planking...then I'd switch to resorcinol.

[rients]

OK Bob. I will get that oil off (I will prevail,as one famous American keeps saying all the time). But about the epoxy I don't know. Let me refrase my question. What are the con's against splining with sikaflex (the one that can be compared with the 3m 5200)??

Thanks guys.

[ 08-17-2004, 10:59 AM: Message edited by: rients ]

[Dale R. Hamilton]

You have to remove the old seam material and creat a uniform space for the spline. I'd do this with a skill saw with 2 or maybe 3 blades in it according to the width of the spline you want to use. Set depth appropriately. I think this will remove alot of the contaminated material and allow you to use epoxy. I really don't thimk there is any metter material for this job.

[Bob Smalser]

I'd use epoxy...and if that don't work well on the oak...resorcinol.

I use the poly goo as bedding compounds, but to me they haven't stood the test of time for your very-permanent application.

[ 08-17-2004, 02:10 PM: Message edited by: Bob Smalser ]

[buhmkin]

Hey rients, I've been thinking about your situation and I gotta ask: how does using sikaflex solve the problem of a contaminated bonding surface? I'm not saying I think it's crazy, I don't, but in my pretty limited experience sikaflex doesn't stick to a contaminated surface with any more tenacity than epoxy. If you use epoxy you can stick to a single system for sealing, splining and fairing. And like Bob said, make a test piece, I'd try a sample length in a grimy spot of seam.

FTR, I think your decision to use a wedge spline (and not square stock)is going to be the major contributor to your success, no matter what you glue it with.

Good luck,
Eli

[rients]

Hi there Eli,

As a stupid dutchy I start to realize that English seems to be the easiest language in the world, but expressing yourself as a non-native speaker is hard, but anyway...

For an explanation of the situation I have to start with the deck of my boat. It is a massive teak deck of 35 mm (1 1/2 inch)which is not watertight and never will be. From time to time there will be leaking water in. In my opinion, in this case, when you think about using epoxy, you should seal the boat from the in- and the outside and maybe even glass her up. Since large areas are conterminated with the oil (and glass will certainly not stick on that), second: all the blahblah about oak and epoxy is not very clear on results on longer term and last but certainly not least the idea of making a tupperware boat of a reasonable sound 80 year old is not very appealing to me, we thought about other strategies that make the hull stiffer and watertight. It is said that some German wharfs are using this technique in this kind of situation....

I realize we have to clean the surface very well and my experience now is that all sikaflex bonds pretty well in the conterminated areas. What you are saying about the wedge shape of the spline as the key to succes sounds reasonable. Do you have any personal experience or tips? Is still have to put some clinkernails in after replacing some of the frames. It seems logic to fasten them after splining, but is it logical?

Good luck to you all
Rients

PS. the Pronautic site, is it the company you work for? The founders of the company seem to have very Dutch names and the projects seem to be rather High end/up market.

[ 08-19-2004, 05:19 PM: Message edited by: rients ]

[buhmkin]

Wow, that was a clear response. I agree entirely with your logic and I don't have any reason to think Sikaflex wouldn't do a great job.

I don't have any tips on getting the job done, except double up with latex gloves so you can keep them fresh, freakin' Sikaflex gets everywhere and your gonna be surrounded by it. A customized skilsaw blade is a pretty popular way of doing it.

And the wedge spline, well yeah I've owned an H28 that had wedge splines and I now have a K38 with square splines. All I can say is that with a wedge spline it is possible to make the hull dead fair and stay that way, whereas with the square spline it seems to be a constant battle. (Maybe it's voodoo, but I suspect it has to do with the fact that a wedge spline results in basically a scarfed seam, and paint loves a scarf rather than a butt, which is what the square spline gets you, essentially).

Yeah, the bosses are Dutch, one by descent and the other's been here about 7 years.

Good luck rients,

Eli

[Bob Cleek]

Well, for what it's worth, here's another opinion. Why spline? I DID look at the pictures. Looks like you have something along the lines of a heavily built spidsgatter, notwithstanding the Netherland's ensign. And, if she's 80 years old, she is certainly well built to have lasted that long. She is a classic.

Splining is a short cut that works sometimes, particularly if it's just in one spot or two. HOWEVER, it creates a tremendous number of potential problems. It isn't only getting the splines to stay put, but also you have to have splines that are going to come and go the same as the plank. And then, many misunderstand splining anyhow. The purpose is to restore the caulking seams, not to replace caulking with a glued up hull. If your splines swell too much, you are likely to start breaking frames. The list goes on and on.

Because your boat is worthy of the care to do the job right, I would NOT put splines in her at all. If you cannot caulk her properly because the seams have been destroyed by some ham fisted idiot who came before you, then REPLACE THE PLANKS. Yep. Replace the plank. Fact is, that this will be less work than splining and will maintain the historical integrity of your boat. She will stay healthy and not bust a gut when she swells. (And believe you me... when she is on the hard and shrinks up, those splines will likely split and tear like crazy!) You only will probably have to replace at most every other plank, since the new one will butt up against the old ones on either side. This will give you two new caulking seams per new plank. Your old planks will serve as patterns for the new (cut proud and planed to fit.) You can plane the edges of the old planks just right to get a new caulking seam all around.

As for your 1.5 inch teak decking... thank God for it. There's nothing better. It shouldn't leak. If it does, it is in need of repaying, if not recaulking. Don't leave it to bake in the sun. (Use a cover.) Keep it as wet as you can. She should stay good and tight, as teak doesn't shrink and swell much at all compared to everything else.

If you are close by, and they are still at it, there are a number of good restorations always going on at the old Dutch East India Dock in Amsterdam, right by the Scheepfarts Museum. They know what they are doing. Nice botteryachts being brought back there!

Good luck. And don't take the easy way out... you'll be sorry! LOL

[Phil Young]

I think Bob is spot on. Recaulk the seams, its going to be way easier and way better than splines. Carvel boats need to be able to move a little, and splined seams just won't do it. Can't see sikaflex bonding any better than epoxy on an oily surface-it won't penetrate the layer of oil on the surface.
I don't understand this-"it is flexible (so the wood is allowed to swell a little, might be necessary because my deck isn't completely watertight)" You'll have very little stretch if the spline is tight in the seam-there's just nothing to stretch. And the moisture you'll get in your planks doen't come from a leaking deck, it comes from the outside, very slowly, right through the planks.
You might try Coelan on the decks. Seems to be a wondergoop that does work. There is arecent thread on this, and a number of old ones.
She's survived the last 80 years, don't wreck her with shortcuts
Good luck!

[imported_Steven Bauer]

I've also read up on splining old hulls. The right way to do it is to glue the spline to only one plank leaving a caulking bevel that you caulk traditionally adjacent to the other plank. First you use a router or circular saw to widen the seam back to fresh wood on both planks. Good luck. She's a beauty. And it's great that you have so much of her history!

Steven

[Spissgatter W-9]

Well there is no agreement as to desirability of wedge seaming a carvel hull. Some like it some don't. This shows up in the advice on the subject. Reputable shipwrights do it with success up here in the Pac NW and I've seen some lovely examples.

I've done it because the previous owner had already made the decision and started things off. I too like the looks of a traditionally calked hull. But if thats not an option or desired then I would offer my experience with wedge seaming.

See two threads: Wedge Seaming Anna Marie http://media5.hypernet.com/cgi-bin/UBB/ultimatebb.cgi?ubb=get_topic&f=1&t=005056&p= and Wedge Seaming Anna Marie II.

Good luck.

[rients]

OK, I guess Spissgatter is right. Very different opinions. In my heart I am with Bob Cleek, but I have run out of time. (BTW, Elisabeth is 35 ft and weighs about 6 1/2 tons, she is fast. I don't know this is heavily built in your opinion Bob, or are you referring to her construction?)

There are little professional caulkers left in The Netherlands, if there are any, and I really need somebody to do it. The past three years I have been thrown from the idea of sellin to restoring and back again and finally my wife and I have made the decision to keep Elisabeth, but make her more manageable (in sailing and maintainance). The splining with sikaflex is for me an acceptable idea, because it means nothing irreversible (epoxy-ing her up would in my opinion). Changing the planking is something I can do any time after this might not work.
:confused: :confused: :confused:
Anyway, I keep wondering what to do.

[Bob Cleek]

If you are leaning towards splines because you can't find a caulker, by all means, do it yourself. It isn't rocket science. Read up on it. (It's easier to do than write about doing, so don't expect to feel secure after reading about it.) Screw a few bevel edged boards similar to your planking to some cross braces on the backs. Fasten it all to a fence or wall and practice a bit before taking a whack at your boat. You'll get the feel of it. Just don't drive the caulk through the seam and out the other side. If you have a really wide seam, some oakum may do the trick. For the rest, cotton will suffice.

Keep in mind that splining is very tedious business. You MUST cut the plank edges perfectly fair, which is quite a trick with either a router or a circular saw. (Battens, jigs and all that for each seam.) Then your battens have to be similarly perfect to fill between each plank, leaving a proper caulking seam... then, well, obviously, you have to caulk anyway, right?

This concept of gluing battens in to replace caulking, with nothing between the planks but the glued batten, is all wrong. Puts undue stress on the hull structure and is very likely to start fastenings and so on.

[Alan D. Hyde]

Welcome back, Sir Robert!

Alan

[Spissgatter W-9]

If time is the only consideration, I would agree that wedge seaming is probably not the best choice.

I didn't experience all the difficulties Bob relates. The batten was easily attached with wire nails, The custom saw blade (not cheap) left a seam with uniform dimensions. The red cedar wedges were easily ripped to fit the uniform groove. (Red cedar is softer than fir planking so will compress when hull is put back into the water.) It wasn't a bed of roses either. All these were bundled in specific order by seam to faciltate installation. (Some kerfs had to be cut into the wedges where curves were tight. They needed to go back into the same spot.) Glue up was challenging by myself. Had to make a trough to hold the wedges as they and the seam were wet out with epoxy. Had to be careful not to mix up to much/little thickened epoxy that was squirted ahead of the wedges with a big syringe. (The thickened epoxy fills any uneveness between wedge & seam.) Had to scrape up the excess. Went through a lot of nitrile gloves.

Fairing went pretty fast. a plane took down the part of the wedge that was proud. The hull looks like it is cut out of a single piece of wood + (or fiberglass -). Its a process to achieve certain goals time saving is probably not enough of a consideration. (Don't know because haven't driven cotton.) But where the circumstances are right, it shouldn't be feared, avoided or eschewed.

PS. Love your boat. My looks very similar. Though built in Norway her designer was Swedish.

[germanreader]

One word of caution regarding Sikaflex and oil, based on hard won experience: Never let Sikaflex ( polyurethane compound)come in contact with oil, as it will dissolve the sikaflex (it becomes soft again). We encountered the problem with our sikaflex deck seam compound as we spilled diesel oil and other solvents on certain areas of our deck. This particular weakness of sikaflex was confirmed by the sikaflex people.

With regard to seam repairs, there was an article by nic compton in classic boat magazine about a year ago. As the planks of a 38 ft Gauntlet appeared too precious to be replaced (knot-free pitch pine), and only the seams were affected, the caulcing seams were repaired by cutting off a strip of each plank on one side of the seams only and gluing in replacement strips with a proper caulcing bevels. It was reported that the amount of labour was probably not much less than for replanking, but the original wood was maintained as well as the original design concept with caulcing seams.
Maybe this approach would be helpful, at least for the hull below waterline where shinkage matters most.
Personally I would trust resorcinol glue for this application, as enough clamping pressure can be applied by soft wood wedges in the caulcing seams.

[rients]

Hi guys,

Thanks for all the input. I'm gonna think and talk it over. I am thinking about something "best of both worlds". I will keep you posted on the progress.

To spissgatter:
I know the danish spidsgatters well. Nice boats. You have the 40kvm as I understood. Do you know anything about the designer (Is it a Berg or perhaps Hansen design). Would love to see some pictures off the outside. Nice job on the inside anyway.

To germanreader:
Danke. I have had the same problem a few years back. You have the same problem with Bottomcoat CR. Keeps the rubber tacky all the time. Must be something with the solvents. I am going to try to remove the oil with turpentine and chalk as Bob Smalser suggested.

To the rest:
Yes of course, Elisabeth is a beautiful classic and I promiss I will not wreck it. :rolleyes:

Rients

[ 08-21-2004, 01:37 PM: Message edited by: rients ]

[Spissgatter W-9]

Reints, my boat is a 40 m2 Norwegian Spissgatter. Not as full in the beam as the Danish spitsgadders. She is posted on http://www.ktkweb.org/styret/Matrikkel/MatrikkelDefault.htm under the name Anna Marie. She as had several names. First Gro III, then Trine and finally Anna Marie. My wife and I decided to use Trine. It seems to fit her best. I'll take some current pics from the outside and post soon.

[JIM MALONEY]

Popeye Cleek
Although I almost always agree with your premises, I do disagree with this latest concerning the use of wedge seams or splines for the repair of a leaky hull - or for the complete re-planking of a hull.
I finished re-planking and the complete renovation my 35' Ralph Winslow cutter this spring using splined seams for the 1 3/8" thick cherry planks. We tight planked and then ran a 1/4" by 1 1/8" router using battens on all the seams and garboard and up the stem. The splines are 1/4" thick Western Red Cedar (a softwood) and are glued in with Aerodux Resorcinol glue (hard to obtain - perhaps I can help) and tapped in. We cut the ends at a 45 degree angle to overlap the joints. After sanding, the hull was treated to several coats of CPES (wet on wet) and then 4 coats of Kirby's Red Lead followed with Kirby's Black. Jack Tarr has been in the water for several months and not a drop of water nor any fractured frames.
I would not use an epoxy glue - in fact there is not a speck of epoxy anything on Jack Tarr.

By the way, Jack Tarr took People's Choice and Judges Best of Show at the Sturgeon Bay Wooden Boat Show a couple of weeks ago.

[Bob Cleek]

Well, Jim, I guess time will tell. There ARE good applications for splining, don't get me wrong. It is, I think, a tricky process that takes a lot of skill. In your case, it sounds like the job was done very well. Since cherry is a very stable wood, it should shrink and swell little. The softwood splines should take the compression and, in many ways, really work the same as caulking. I'd think this approach won't put any undue strains on the fastenings and frames. Too often, folks spline with the same material as the planking. This results in a monocoque hull skin, which is fine if the framing is designed for it. (Not unlike cold moulding.) But, if the framing isn't designed for a monocoque skin, when the skin shrinks and swells, it can tear itself right off the "bones."