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tillergirl
05-11-2013, 05:36 AM
The 'wales on Tiller Girl are each three 14ft by 14" x 1" iroko planks scarfed into one 32ft length on either side. Approx half of the depth is below the deck line; the other half is (obviously) above the deck line but unsupported by frames. A number of scuppers at the deck line are cut into the rear half of the 'wales'. The originals lasted from 1964 to 1997 when deck repairs led to their replacement. The replacements (like the originals) have some shakes radiating from the corner of a couple of scuppers but more importantly due to a dork bit of helming, I donked the corner of a dock last year and put a nasty crack some 4ft in length on the starboard quarter.

The crack does not go right through the plank but I can - just - open the crack very slightly. However, I cannot open it sufficiently to get any significant amount of glue in there. So what to do?

My (best?) idea so far is to remove the capping rail this winter and drill down a thin (quarter of an inch?) but long hole down the middle of the plank beyon the crack and insert and glue in either a bronze or stainless rod. Challenging to get the hole straight and true given the twist and sheer but I think it might be possible. Anybody got any views on this or alternative suggestions? First image is from 1997 showing the repairs then; second image shows the current crack.

http://i217.photobucket.com/albums/cc151/rgaspar_album/scan0004-1-1.jpg (http://s217.photobucket.com/user/rgaspar_album/media/scan0004-1-1.jpg.html)
http://i217.photobucket.com/albums/cc151/rgaspar_album/P1000652.jpg (http://s217.photobucket.com/user/rgaspar_album/media/P1000652.jpg.html)

kc8pql
05-11-2013, 09:04 AM
Having trouble seeing the crack. Is this it?

http://i41.tinypic.com/23l6rl.jpg

tillergirl
05-11-2013, 10:11 AM
Yes - plus it extends the other side of the forward scupper. It is a fine crack but definitely there.

David G
05-11-2013, 11:05 AM
Would this work? Neat epoxy in a syringe with a fine gauge needle. Flex the crack open. Inject plenty of epoxy. Release the flex. Mop off any squeeze-out.

tillergirl
05-11-2013, 11:25 AM
I guess it would work to a degree but the crack is very small. There would be little strength in the glue joint since I would not be able to get to any depth. But it would seal it from the weather which is certainly one consideration.

David G
05-11-2013, 11:46 AM
The point of using the syringe is so that you can stick the point deep into the split (even to the bottom?) and inject glue. Then... allowing the flexed crack to close back up will squeeze the glue deeper and further, and any excess will squeeze out where it can be mopped off.

The alternative, as you say, is to rout/saw out the split, and glue in a a dutchman.

The latter is more work - but if you can conceptualize it better than the former... it might be preferable for you.

Jay Greer
05-11-2013, 11:55 AM
The problem involved with this kind of crack is that there is no way to clamp it if it is to be glued. If it is not clamped, it will open and shut with changes in weather and dampness. Splining it will be diffifult and will always be obvious. So, it is truly a delemma! I would approach it by using a correct taper drill and jig boring for long #10 or #12 screws right down the middle. A Stanley #59 Dowling Jig will work well for this. If the screws are first dipped in melted bee's wax they will drive more easily. Prior to driving the screws some kind of glue should be forced into the crack. This can be done by first taping off the sides and using a putty knife to force it in. I talk about it a lot on this forum but, West System G/flex is your best bet for longevity here. Once the screws are home, the squeeze out can be removed with a putty knife and when the epoxy is dry and the tape is removed and sanded, the slight color of the glue line can be tinted using a striping dagger with artist's or sign writer's oil paint of a slighly darker brown than the wood itself. Here is one place where a good slot matching screw driver bit in a brace is the best set up to drive the long fastenings.
Jay

JimConlin
05-11-2013, 11:57 AM
I've injected epoxy deeply with the syringes sold in home healthcare shops as irrigation syringes. Their tip is tapered about 1/4" dia. and wedges tightly in a 1/4" hole. You can exert considerable pressure and deliver up to 60ml.
Drill a 1/4" hole into the crack from the face, 3/4 the thickness of the timber, flex the crack open and force feed epoxy until it oozes out. Add a 1/4" bung and clean up later.

Gib Etheridge
05-11-2013, 12:32 PM
How would it look if you applied another layer of 3/8 from the deck line to a ways above the top of the scupper for most of the length of the iroko? You may be able to fashion it so that it looks nice, as in an accent piece. Before doing that get a hypodermic from the pharmacy and fill the crack. Once that's hardened sand it smooth and bed the new layer in epoxy with 8 ounce cloth between the layers. Hopefully that will strengthen the area enough to avoid further trouble while covering and sealing off all of the cracks and checks. Since the edges of the scuppers are rounded over you might need to enlarge them just a bit then round over the new work. I wouldn't dare to attempt boring down from the top for that much width, it would look like hell if it ran out.

tillergirl
05-12-2013, 03:39 AM
Thank you all for your contributions which I am still thinking over. I guess I have two objectives. One is to 'weatherproof' the crack which as Jay has said will open and close with the weather/conditions. The other objective is adding a bit of strength to prevent the crack developing into something worse.

I am thinking that the various suggestions regarding 'injection' of epoxy will work to a degree but I agree with Jay that the crack will need to be squeezed. The Stanley jig is a vast improvment on the 'hobby' dowling jig I have and I must see what I can find. I really don't fancy splining - shape of the crack/proximity to the rubbing strake etc will make it difficult and my shame will be there for everyone to see. Gib - I take your point and I'll offer up an offcut and have a think about what might be done.

I take you all think that the 'rod' idea is a bit daft? My thinking was give a bit of strength back to a section that is obviously weakened by this clump.

George Ray
05-12-2013, 04:55 AM
One or two or three pins to reinforce the cracked portion. Most welding shops will have silicon bronze tig rods as big as 3/16" and only challenge is making a drilling jig to keep the 'long' bit centered and then be careful not to penetrate the covering board. No need for the pin to be large as a small rod is strong enough in shear strength and going larger only serves to weaken the rail considerably. Edge drilling is fun and challenging. The jig can be a simple as piece of wood clamped to the 'wale' with small spacer block so the 12" drill is centered. I often just use eyeball to keep long drill bit and and guide stick parallel.

*************
Related drilling tip:

http://www.yrvind.com/present_project/?m=201210


October 24, 2012
ON RIGHT ANGLES
Orthogonal, perpendicular, normal, square and right angle, we have many names for the things we love. And right angles are one of the cornerstones of our modern civilization and for good reasons, without them everything would be crocked. It is so basic that even our Euclidian space is defined by it with the help of the Pythagorean theorem.

Even boat builders are well served by right angles. But it is not always easy create them.

Here is a trick. Use a mirror. A straight line reflected into a mirror continues as a straight line into the mirror only if it is at right angles to the mirrors surface. The pictures below illustrates the point.

http://www.yrvind.com/present_project/wp-content/uploads/2012/10/PA220061-400x300.jpg

In the picture below the stick is at right angle to the mirror.

http://www.yrvind.com/present_project/wp-content/uploads/2012/10/PA220060-400x300.jpg


http://www.yrvind.com/present_project/wp-content/uploads/2012/10/PA220067-400x300.jpg

tillergirl
05-12-2013, 05:19 AM
George - thank you. I like the mirror idea!

I am thinking of a belt and braces approach effectively taking each of the three ideas - one: a number of pins to provide reinforcement (with a plan to ensure the accuracy of the hole!), two: Jay's 'screw approach to closing the gap, three: epoxy into the crack. I guess I should have put those in the order 3, 2, 1 (3 and 2 being done at the same time).

Redeye
05-12-2013, 05:27 AM
If you have a friendly doctor, nurse or crack addict in your circle you may be able to get some clean, single use hypodermic needles, these are great for very fine crack. :)

The mirror trick is great... How well does that work for the operator as the observer? When you observe it from a distance I can see it works well, but can you see past the drill? I guess you can then hold it as a distance...

Gib Etheridge
05-12-2013, 10:37 AM
Not looking for an argument, but I don't think any of those three methods, or all three combined, will work as well as covering the cracks with added thickness. Screws from the top will have to be very long. Metal dowels won't accomplish much, in fact if you bed them in epoxy they will actually promote cracking because as the plank becomes wider and narrower with changes in humidity and exposure to the hot sun the epoxy and pins won't change at the same rate and something will have to give.

tillergirl
05-12-2013, 11:25 AM
Not looking for an argument, but I don't think any of those three methods, or all three combined, will work as well as covering the cracks with added thickness. Screws from the top will have to be very long. Metal dowels won't accomplish much, in fact if you bed them in epoxy they will actually promote cracking because as the plank becomes wider and narrower with changes in humidity and exposure to the hot sun the epoxy and pins won't change at the same rate and something will have to give.

Umm. Good point.

dinoa
05-12-2013, 11:36 AM
Maybe cyanoacrylate super glue which is much thinner could be injected. It also wicks better. Overlaying with epoxy or PU will protect it from water.

Dino

Jay Greer
05-12-2013, 12:11 PM
I must reinforce my first statement that the crack will open and close with changes in weather. For this reason, you will need an adhesive that is flexible and also has slight gap filling capacity. When we did the double planking on the Herreshoff Steam Launch "Vapor" West System Gflex was chosen because it imparts all of these desirable factors. It is best applied with a putty knife as it is too thick to be applied with a syringe and the knife will force it into the crack very well. Any glue that does not flex will eventualy tear apart. Screws are also the best choice due to their capacity to draw the joint together. The Stanley #59 is also the most trustworthy drilling jig as it is simple to use and can be adjusted easily for centering. One thing that should be considered is that, if screws of sufficient length cannot be found and shorter fastenings are needed, then the holes must be step drilled in order to place the heads further down into the rail. This will require a bit of creative thinking on the part of the mechanic doing the job.
Jay

Redeye
05-12-2013, 12:18 PM
Just a question,
How long do you think this has been cracked?

If it's been this way for 10y, maybe it doesn't really matter...

It's in the bulwark, after all, and not a vital structural member, unless I'm mistaken.

How do you think it cracked?

tillergirl
05-13-2013, 01:59 AM
Just a question,
How long do you think this has been cracked?

It's in the bulwark, after all, and not a vital structural member, unless I'm mistaken.

How do you think it cracked?

I 'clumped' (olde English term for 'hit') to corner of a pontoon last Autumn (olde English term)! Reversing from the fuel pontoon I misjudged the effect of wind and tide and had my attention drawn forward for a critical moment. Although I only struck very slightly, 7.5 tons is 7.5 tons and as observed it is not a vital structural member and is poorly supported for precisely the angle of strike that I achieved. It was entirely my own fault and cancels out any number of previously faultless manoevres!

Jay - I am with you entirely. Reflecting on Gib's point of creating the risk of cracking, the silicon bronze screws in the Hood Ends don't promote cracking. If I use Jay's method for tieing down the crack and long pins inserted without glue to bolster the vertical support I wonder if I could avoid that happening. The screws would need to be fed down inside clearance holes to prevent excessive length.

I am though coming to the conclusion that scarfing in a new rear section of 'wale is the only real professional solution. And since the crack goes a little forward of the last scarf, I know I shall have trouble sourcing timber of sufficient length.

Oh the penalty for a moments mis-judgement!

Chip Chester
05-13-2013, 07:34 AM
To get glue into a crack, I've read (somewhere -- maybe WB) that using a shopvac or vac pump to suck it thru the crack works pretty well. In this case, a long bit of plastic with a hose connection taped (generously) to one side, then glue applied to the other side of the crack. Maybe make a lever to flex the board back and forth for best adhesive penetration, then clamp, stake, drill/screw as required to snug it down for curing. If you use a shop vac where the incoming air goes thru the motor, use a non-flammable glue.

Chip

James McMullen
05-13-2013, 08:01 AM
Why don't you just replace the cracked section of the plank? Scarph in a new section?

wizbang 13
05-13-2013, 08:32 AM
That is a 14 inch tall plank? Half of it is below deck level? You mean the toe rail/bulwark is the same ACTUAL plank as the sheer plank?

That seems a screwy way to build a boat. What would happen if the bulwark got really badly nocked, would it break the sheer plank?
I am taught a toe rail should not be able to lift a covering board or loosen a sheer plank. It looks like such a good boat!
Anyway, I would either run a skilsaw kerf in there and fill it with epoxy, or fit a dutchie. Actually I would just kerf it and fill it.
Or, I might cut the WHOLE thing off at the deck and stick it back on, weakly.

Canoez
05-13-2013, 08:39 AM
Just one thought on epoxy bonding - while it does work well (If you could get the adhesive into the crack - we've used vacuums to help draw epoxy from a surface into a crack with good luck, BTW.) many folks tend to over-clamp epoxy joints and can actually push the adhesive out of the bond area if not careful resulting in a weaker joint.

Mrleft8
05-13-2013, 09:28 AM
Bronze doesn't glue well.... I think I'd be more inclined to use a butterfly or Bowtie Dutchman.
Properly done they are a good honest repair and they can be quite decorative if you choose your material well.
Stronger than a dowel or rod in a hole, and harder to screw up.

kc8pql
05-13-2013, 11:42 AM
I think I'd be more inclined to use a butterfly or Bowtie Dutchman.
Properly done they are a good honest repair and they can be quite decorative if you choose your material well.

+1, and because they don't need to be nearly as long as the rod/screw solution, they're much less likely to restrict normal cross grain wood movement to a degree that would be detrimental.

tillergirl
05-13-2013, 04:25 PM
That is a 14 inch tall plank? Half of it is below deck level? You mean the toe rail/bulwark is the same ACTUAL plank as the sheer plank?

That seems a screwy way to build a boat. What would happen if the bulwark got really badly nocked, would it break the sheer plank?
I am taught a toe rail should not be able to lift a covering board or loosen a sheer plank. It looks like such a good boat!
Anyway, I would either run a skilsaw kerf in there and fill it with epoxy, or fit a dutchie. Actually I would just kerf it and fill it.
Or, I might cut the WHOLE thing off at the deck and stick it back on, weakly.

Well I didn't design her! Built by a company that used to build Bawleys on the Thames Estuary before that business dried up and they moved to Yachts. I guess my experience is that if it got really badly knocked it would just break above the sheer! And I guess such a strike would do damage to planks and frames anyway. Replacing the damaged section of course is a serious option but an amound of work I would really like to avoid.

Regarding the other posts regarding filling the crack - the crack does not - at the moment - go right through the plank. It is a pretty small crack - well in width. Hadn't thought of a butterfly so far. Must think about that. That might be the best given the other difficulties.

Thanks Gents for all the comments.

By tghe way, here she is in action:

http://i217.photobucket.com/albums/cc151/rgaspar_album/Dscf5019.jpg (http://s217.photobucket.com/user/rgaspar_album/media/Dscf5019.jpg.html)

http://i217.photobucket.com/albums/cc151/rgaspar_album/Blackwater-CJP17.jpg (http://s217.photobucket.com/user/rgaspar_album/media/Blackwater-CJP17.jpg.html)

Jay Greer
05-13-2013, 07:56 PM
One parting comment I might suggest is, to start with the easiest and most logical approach first. If that doesn't work then, go for the complex solution.
Sweet boat!
Jay