View Full Version : Cracks & Holes
09-30-2009, 12:14 PM
I have an old split in the teak cabin side, which has been there for ever it would appear. Could anybody suggest an idea for a stable, lasting repair?
I do not use epoxy, I never have and wouldn't know where to start with that medium - I imagine at some time I will have to - in the meantime a non-epoxy method would be preferred if that is possible.
Also what are your favoured filling options for dents, holes, screw heads etc. (not plugs / bungs) and how would you colour to blend in with the repair surface (I'm assuming sanding dust will figure here)
09-30-2009, 12:19 PM
You could replace it. It looks like its just held there with screws.
09-30-2009, 12:25 PM
Yes - I could, but it's 16ft long, 1ft wide, 1.25 inches thick and been on the boat for over 100 years, hopefully you can appreciate my reluctance to do so!:D
10-01-2009, 01:18 PM
I hope this helps mate.
If it's that old leave it alone.
Scrape off the finish clean out the cracks and glue in a "splinter" with Tightbond III
10-01-2009, 07:15 PM
Clearly is doesn't Kiwi, the poster said no epoxy. Also as this is a cabin trunk it would be quite unsightly.
There was a recent article in our hosts publication about more natural fillers and such. I have had good success with their rosin beeswax mixture. Heat the beeswax till it is soft like peanut butter and begin to stir in rosin. Keep going till it won't take any more rosin, then putty in, let cool and trim flush with a sharp chisel. The color should be a reasonable match.
I recently sold a 1915 Crosby Catboat that still had this mix over the original fasteners. Smelled strongly of pine every time I removed it, came out nicely but was very solid. Could be a reasonable solution. Reef out the cracks to get all the paint out and have a go.
10-01-2009, 10:04 PM
I don't think you would finish something bright like my, to be painted, mess but was attempting to suggest that a piece of timber be set in flush and span the crack. I don't think just filling a crack is all that strong, it'll probably do it again. I would do it on the inside and make the strip of timber about 1/2 the thickness of the cabinside there.Just because I am a mad butcher and I like making things TOUGH.
All the best mate.
10-02-2009, 01:25 AM
I like the approach by Oakman; as he says this case is really a lasting cosmetic repair (not helped by summer heating and contraction in the sun).
My only question would by; how does the beeswax content affect adhesion qualities of the subsequently applied varnish?
10-02-2009, 08:50 AM
Well that is a good question. Paint, at least traditional paint, does not seem to have a problem sticking. Perhaps looking for the article and checking with our sponsors could provide a better answer. Once the process of mixing is complete there seems to be almost as much, if not more rosin than wax. The bees wax is somewhat sticky itself and I believe the rosin helps in the adhesion. I believe that Jay Greer advocates priming deck seams with a mix of turpentine and beeswax and has no problems with adhesion of traditional compound like Jeffrie's Marine Glue for deck seams.
Make up a test and try some varnish on it. That would be the best way to go.
Kiwi is suggesting a dutchman, which could be a good idea for a fix if the cracks are leaking or go all the way through. Especially if you want to keep the piece, which you do, and minus all the extra epoxy this is an excellent way to preserve as much original wood as possible. The trick is matching the expansion and contraction properties of the original wood so the dutchman does not cause more damage than what you are trying to fix.
10-02-2009, 09:06 AM
Try painting the wood with ethylene glycol antifreeze. So long as the finish is neither epoxy nor polyurethane, the glycol will penetrate and swell the wood to close the crack.
10-02-2009, 09:21 AM
Try Dave's glycol treatment. Otherwise other than something soft like beeswax to slow any seeps or leaks, you are wasting your time, and should consider the cracks part of the character of the boat. Don't squirt anything that hardens in the crack ir it will act as a wedge and make the cracks worse next summer, not better.
While Burmese Teak is a very stable wood, the side shown is a single, 12"-wide, flatsawn board screwed down tightly at the ends by screws. The cracks you see after a summer of baking in the sun are merely annual measurements of the seasonal movement this manner of construction prevents.
It'll all just reoccur if you don't either change the construction to allow unimpeded seasonal movement or coat/saturate the wood with something that slows down moisture passage sufficiently for the wood to reach the next humid season before it cracks again from drying in the summer sun. Your cabin top appears to have been originally painted, and paint is more effective slowing seasonal movement than varnish.
Your cosmetic problem is compounded by oxidation of the wood surface and water stains in the crack from years of moisture intrusion. All these cosmetics can be repaired, but probably not while the board is in place on the boat. I wouldn't, but if you do try a splinter and glue, use a urea resin glue, which won't interfere with later bleaching and staining if you or a future owner ever decides on a permanent repair during a full restoration.
10-02-2009, 10:20 AM
If you think the movement is continuing, I'd very carefully stop drill the end of the crack as well. If this crack has been in there for a long time, say a number of years and seems relatively stable (as can happen), then gluing in a small spline (or"splinter) will be a reasonably tidy fix. Usually cracks like these do go all the way through but don't seem to leak visibly unless the boat is underway. You can tell if water is getting through by looking at the crack after a run in seas. Then you might see salt along the seam on the inside. If that's the case, a spline recommends itself, usually on the outside. If not and there is no leaking, periodic varnish is satisfactory and you are left to repair breaks in the surface finish seasonally as you fit out.
Filling with wax or oil based compound is a temporary fix, and that's ok, but any finish you apply there will crack out and break at the seams in relatively short order as water works it's way behind the compound or wax into the crack.
There's no really perfect and invisible fix without replacing the whole plank, but a properly done small wedged spline glued in is going to be as permanent a fix as you will find under the circumstances. I wouldn't worry too much about compression set in this instance as the damage is already done. Actually, he repair might benefit from widening the outside face just a bit so a good spline can be made, but if you can manage a narrow splinter to fit, good enough. These sorts of fixes never bother me to see; they are part of the boat and inevitable on old vessels. If they are well done, they display care and craftsmanship. Watching these problems over time often helps you make up your mind regarding what sort of repair you want to do, so in this case patience can be a virtue as well.
Otherwise, it's some sort of wax or compound which will break out seasonally from time to time and simply becomes part of the battle scars of an old boat. I'm not sure the aversion to epoxy unless you have developed an allergic reaction. But any good waterproof glue as recommended by Bob will do.
In respect to repairing major dents and dings; it really depends. If they are horribly deep, dutchmen. If not, keep filling with finish until the surface is level.
Most big boats really don't lend themselves to the sort of fussy/crafty steaming and filling that significant antique restoration or gunstock repair might respond to if it takes a minor ding. There's usually just "too much boat" to approach problems that way. But for filling holes, you have really got two choices: fill with goop or a plug. Again, I'm not sure why the aversion to a plug/bung, but I suppose "if you must" you can do a trompe l'oiel repair and match paint grains with a filled hole or dutchman. But again; on an old boat making repairs to this level of detail is going to lead most sane people to madness eventually.
10-02-2009, 10:28 AM
Hiya,there are lots of right ways to fix,this is my fav-:p mix 25% beeswax with 75% rosin ( rosin is the distillate left over from making turpentine ...looks like amber) heat and mix,use a spackle to push into the crack or placed in area too shallow for a bung...its paintable,sandable,moves with the exspan/contraction of the wood,...if you mix more beeswax then 25% you cannot use above the waterline, hope this helps
10-02-2009, 12:35 PM
whatever you choose can be supplemented if you wish with a 6 mm coppper rod , or stainless about 100 mm away from the porthole driven blind thru the centre of the coaming vertically from below, thru the carlin if applicable, to within 30mm of the roof , you can practice on a scaffold board or other with a guide flat to the coachroof side, it will stabilise the movement if it concerns you
10-02-2009, 01:57 PM
Very many thanks for your time gentlemen.
Bob: the cabin has never been painted - I can say this with some certainty, maybe it's the glare from the flash?
Some background: this is a boat my father raised as a sunken wreck in '47 and rescued from certain destruction. In the last 5 years of his ownership, I came along and spent many happy days on her until he sold her in '67. I then spent 41 years dreaming of the day I would buy her back - this happened in March this year. I do know something of her history, what has been done to her and largely by whom in the intervening years....
If I try the Glycol route, will that have any implication on any other treatment in the future?
With regard to the weather staining - what would be the best way to reduce this? Oxalic?
You mention changes to construction to prevent re-occurence, what would you suggest and what aesthetic implications would this have?
Lew: re the short history above, I can't be sure exactly how long these cracks have been present; it could be 5 years, it could be 50 years!! Also, you are right they do go all the way through. Weather wise it's not normally a major problem - these boats are characteristic of a specific (and relatively sheltered) inland water system and are captive within it, weathering is restricted to sun & rain, though some rain has obviously penetrated the inside at some time.
I couldn't really contemplate new planks (both sides) for a couple of reasons - the cabin sides constitute some of the few remaining original parts! and I couldn't see how I can afford the Teak to replace it!!
Perhaps your suggestion to hold fire and observe for a couple of seasons is the best way forward - but you know how it is, you like your little girl to look her best after a major refit!!
Reference bungs / plugs, I have no real aversion, it just is that sometimes a fill seems more appropriate eg fixings for cant rails etc that one expects to remove on a fairly regular basis or a breakout chip that doesn't lend itself to a circular bung / plug
Peter: your copper / stainless tie rod aproach - would this be in the form of threaded rod?
10-02-2009, 02:28 PM
if you are removing the roof covering you can bolt it, but it may be that you dont need to
it may just need keeping in line, which blind rod will do
if you want to pull it together without disturbing the roof, as far as i can tell, the deck is off ,so
you can clamp it together, with sash cramps & softwood pads
then from below, drill a countersink for the nut socket/ washer,
if you want to grain plug it, marry the plugcutter to countersink first,
then drill 6mm to the crack, then
you'll have to practice this for the right diameter, maybe 4-5mm pilot for a screw studbar / allthread, which acts as a long woodscrew
or you can die thread copper rod
whitworth not metric as its coarser
be very careful, lock one end with loctite, or locknuts & treat it as a screw
you can grease the screw
not the countersink
for the later glue over the nut
10-02-2009, 03:02 PM
.... raised as a sunken wreck in '47 and rescued from certain destruction.
....If I try the Glycol route, will that have any implication on any other treatment in the future?
With regard to the weather staining - what would be the best way to reduce this? Oxalic?
You mention changes to construction to prevent recurrence, what would you suggest and what aesthetic implications would this have?
Going from a submerged moisture content through a couple-few seasons of dry summers explains the cracking much better than going from paint to varnish.
The glycol soaking gradually replaces the water in the wood with glycol. Once dry, it can be both glued and varnished without problems. Many are deadly poisons with a sweet taste however...banish any kids, dogs and cats elsewhere for a few weeks.
Those exposed fillister screws near the left cabin corner in your photo look like something was added. I would expect them to be countersunk and bunged if they are an original construction feature of the cabin. Perhaps they can be removed and whatever they are holding reattached so the cabin side is freed up to move seasonally. If not, unless there are other problems rebuilding the cabin if desirable can wait for a later restoration.
I think Peter's solution of pulling the crack tight using a copper or bronze drift is a good one. Especially if the ends can be accessed and threaded on both ends to make a long, washered bolt out of it to pull those cracks closed. The edge grain will crush some around the washers as the wood swells in winter, but unlike the cracks you won't be able to see it.
Once the cause of the crack (impaired seasonal wood movement) is solved, repairing it is easiest done on a horizontal surface as part of a major rebuild. There the crack is most easily cleaned, bleached with oxalic acid, filled using dyed epoxy color-matched to your stain, stripped, stained and the crack hidden using pigments beneath the varnish. If you do the drift repair in place, you can install the drift (nicking the sides of the drift with a chisel to provide further resistance to wood movement) strip the varnish over the crack area, build a clay or tape dam to soak some oxalic slurry into the crack to remove the stains, and let it close on its own over your wet season. Then next spring you can strip, stain, hide the crack with pigments, and revarnish. Or....if you limit your stains to water-based aniline dyes, you can strip and stain the wood first before trying to colr-match your epoxy. Just keep in mind that generally, mechanical repairs are best done before stripping and staining and oil-based stains and fillers will interfere with gluing.
Under no circumstances would I rout out a straight line for a dutchman....if I were doing that type of repair I'd tap fit in a thin, flexible wedge instead using urea resin glue. Other glues can interfere with staining, and straight lines are much more difficult to hide with stains and pigments than lines that follow the grain of the wood.
Here's a method for drilling for drifts without any specialized shipwright tools you may not have access to:
Traditional Centerboard and Case – Part I - The Board
10-03-2009, 04:37 AM
Much to absorb, gentlemen - thank you very much.
Bob: the screws I still think are original, they attach the cabin side (and front) to a large decorative internal corner block, there is no evidence of any other prior way of forming the cabin "box".
10-05-2009, 02:44 PM
Dumb question: what kind if rosin?
This might work for my crack in the cabin side (replacement way beyond our scope)
ive had good luck with beeswax too, in bilge applications so I'm somewhat comfortable with it's use.
10-05-2009, 04:50 PM
......what kind if rosin?
The cheap, 6-dollar a pound kind. Rodeo rider's rosin.
Crush it to a powder in a mortar and pestle and mix with melted beeswax for a putty that gets firm but not over-hard, can be painted over and is resistant to heat, wear and tear.
10-06-2009, 10:46 AM
Thanks Bob, guess I have to round up a cowbow ;)
If you didn't get an answer to the oxolic question let me know, I'm using it at present with much success. Actually neutralizing this afternoon.
Powered by vBulletin® Version 4.2.1 Copyright © 2013 vBulletin Solutions, Inc. All rights reserved.