H28 "Larrikin" rebuild

[Larks]

You could step the beam into the carlin in such a way as to run the bolt through both members, just to be thorough. And to show that you just can.

Which beam do you mean Kerry?

[Larks]

I didn't bother photographing the process of the second knee, but suffice to say that after working through the first one, the second was fairly quickly and enjoyably turned out:

so after a bit of final sanding:




and a liberal dose of everdure all around, a nice pair of quarter knees ready to go in:

[floatingkiwi]

Which beam do you mean Kerry?

Oh yes. Aah, the half beam. Just thinkin out loud. This should work.

[Larks]

They are all notched into the carlin but the same way as shown in the last two sketches of your post #643.

[RFNK]

It doesn't feel right saying I really like your knees Greg, but I do. Excellent!
Rick

[Larks]

It doesn't feel right saying I really like your knees Greg, but I do. Excellent!
Rick

thanks Rick, I'll get them fitted during the week with luck

[P.L.Lenihan]

thanks Rick, I'll get them fitted during the week with luck

What? Lucky Luke is getting his knees done too?! I'm impressed!


Fantastic progress Greg and the pictures are getting better and betterer!


Cheers!


Peter

[RFNK]

H28 devotees might not want to see this but:
http://www.ebay.com.au/itm/Classic-y...item2312c64c83

If it's too painful, let me know and I'll delete the post - yes, Jay, I'm thinking of you!
Rick

[Larks]

H28 devotees might not want to see this but:
http://www.ebay.com.au/itm/Classic-y...item2312c64c83

If it's too painful, let me know and I'll delete the post - yes, Jay, I'm thinking of you!
Rick

That's the one that Duncan (I think it was Duncan?) reckons Peter should buy. At least it's getting a few bids, might be worth the effort if the hull is actually OK.

[Larks]

A couple of quarter knees in place. I've everdured and varnished them and won't be painting them otherwise. They'll probably never be seen under here again once I put the deck on but I am much happier with these and quite like the look of them just as they are:

Here's a nice cropped shot that gives the impression that the hull is all nicely primed inside:





And now here's a more honest one:

[PeterSibley]

[Larks]

OK, I need some input - it's time to get a bit more serious with another little problem area that I've been procrastinating about while debating with myself just exactly what to do.

Dealing with an open glued seam in the strip planking.

I have asked about this quite a while ago and have been considering some of the ideas raised but am just wanting to open this up again before I go ahead to see what other ideas may be out there.

I do have a few glued seams that have failed but this is by far the worst and the only one that has actually opened up to show daylight right through and to jump across to another seam. It has obviously been a problem for a while as there has been sikaflex (or similar) shoved in there sometime in the past.

Just remember, this is a resorcinol glued, huon pine strip plank hull, so none of the seams are caulked, other than the garboard and other deadwood seams.

So here is the offending cavern:




and this is where it jumps across seams, splitting one strip in the doing:




Of the 28' hull, this split runs from the transom (where it closes up to nothing) forward about 10', being 6' along one strip - the most cavernous part, jumping to the next one up for about 2' before dropping back down to the original for another 2' or so. The pic' below shows the first 6' where the paint is stripped up until where it jumps to the next strip:




So, as suggested above, the first job when I got home from work this arvo was to strip off the antifouling along to get a decent look at what I have to deal with.

This shows the widest gap along the seam, the camera angle is a little deceptive but it's about 6mm:



Or for those still in the dark ages:



Here you can see where there was sika in the seam - which incidentally had been working as the hull was nice and dry when I picked her up. However I'm quite sure that she has opened up more this time around than she ever had in the past, causing the split across planks

[Larks]

The vary aft area showing how the split closes up to the stern:



Moving forward, the same split in the planking itself shown earlier where it jumps to the next seam up:



and moving forward about 2', where it drops back down to the original split:



And a view along the whole split from the transom:

[m2c1Iw]

Question, how is the bath going down lower. If it's working do you strip some more antifoul and lift her skirts a bit higher to see what happens. I was going to suggest epoxied spline but I'm not sure that would be wise on a dry hull. I qualify this comment by saying I have no idea what I'm talking about. Good luck though.

Cheers
Mike

[Larks]

Now, about the solution to this little conundrum:

As mentioned, this is a resorcinol glued, huon pine strip plank hull..... and.....as well as being copper roved to the frames, it is copper nailed across each plank into the next in a staggered pattern, not necessarily always along the centre line of the plank.


This sketch shows roughly how the nail pattern runs. As you can see, along the opening there are not only a series of through nails but also the tips and tops of other nails either edge of the opening:



I know the profile makes it look like the nails are all on top of each other, however the lower sketch is meant to show how they are actually staggered across the planking.

The problem that this creates is that it is not just a simple exercise of routing or sawing out along the strip to create a V'd slot to glue a nice long V'd spline into.

It also means that it is not a simple exercise to clean out all of the old resorcinol glue to get a clean glue/epoxy bond to the planking.


And now the following one shows a few very rough sketches of the options that I have been considering. I haven't actually sketched all options but these show the basics of what I think may be done, either alone or as a combination of two.




Sand as much resorcinol glue from opening as possible using thin steel strip with sandpaper stuck to it, then:

Option 1: Shape a single 1'' wide strip of huon pine with tapered ends to follow the shape of the opening and epoxy glue right through the hull to the inside edge.
Check slots out in the huon pine strip to clear the nails by tapping the strip in first to mark it then cut slots into strip before gluing in place with thickened epoxy (or Fixtech "fixit mate" polyurethane glue - pending outcome of current testing on water tight integrity of this product - but that's another story).

Option2: (My preferred option) As per option #1, but add a fibreglass strip set into the hull side covering at least next seam onto next plank either side.

Option 3: Route shallow V grooves either side of split to allow V'd splines to be set into hull either side and sanded back flush. These would need to be shallow enough to avoid routing into any nails but deep enough to be worth doing, they would probably make about 8-10mm or a bit over 1/3" either side (the hull us just over 1" thick).
Glue in with thickened epoxy to fill the void space between the splines
Set in fibreglass strip on outside of hull as per option #2
The interior splines would not be set in behind the hull frames, that area would need to be filled with thickened epoxy

Option 4: As per option #3 but with no internal spline, instead fill void with thickened epoxy.

Option 5: The no spline option......fill the void with either:
a. Thickened epoxy
b. Sikaflex
c. Fixtech MSP15 or MSP190 http://www.fixtech.com.au/process/catalogue/itemView.html?itemId=3123&categoryId=571
d. Slickseam
e. Lead putty, linseed oil, antifoul goop mix


OK so them's the options that seem to be feasible in one way or another, albeit some more so than others.

I'd add that although the hull has dried out to create this opening, the huon pine is actually quite dimensionally (?) stable so I'm not overly worried about what stresses closing up will cause when she gets wet again if I fill this gap (except with something completely unforgiving like thickened epoxy), however I have seen that when I've kept it moist for a while during the wet season it does still close up somewhat. I'd say that it's fair to consider the huon pine's current state to be sililar to how it would be if I was building the hull from new (though that is only my opinion).

With that in mind, my most preferred option is option #2 above.

My least preferred (for this particular seam anyway) is option #5 and of those just filling with the thickened epoxy is my least preferred.

The option to just fill the seam with Slickseam or Fixtech may well be suitable on the glue lines that have failed but haven't opened up like this one, but I just can't see it working on this one as a long term fix.




So............what are your thoughts??? Please give all and any ideas as this exercise is all about giving me more to think about and opening up other potential options - even if your idea leads on to something else.

Obviously replacing planks here is not all that feasible because of the way the planks are nailed, though I have certainly thought about how I might actually do that and it may be achievable by diagonally nailing back into planks either side, however I doubt that it would be any more suitable than any option above.......though if anyone has a particularly good argument for that?????

[Larks]

Question, how is the bath going down lower. If it's working do you strip some more antifoul and lift her skirts a bit higher to see what happens. I was going to suggest epoxied spline but I'm not sure that would be wise on a dry hull. I qualify this comment by saying I have no idea what I'm talking about. Good luck though.

Cheers
Mike

The bath "seems" to be going well Mike, I'll probably drain it and have a look in a week or so, I'll check the control samples that I have this weekend and see if they are still moving.

I don't think it's worth soaking this area up, it needs repairing regardless and I've been able to see that it does close up only slightly during the wet season when I've kept it wet for a while. It's really just a matter of choosing the repair now and getting it done then sealing the hull both sides to keep it stable while I do the fitout and everything else.

[m2c1Iw]

Yep OK FWIW I think I'd go with your option might just cut as many nails as possible to try and avoid a stuff up when everything is covered in goo plus run a strip of glass on the inside as well. It will be interesting to see what the experts have to say.

[Candyfloss]

I would not have thought that copper nails would bother the tungsten carbide tips on a router bit very much Greg. It's going to take a few passes, & maybe even a few router bits, but my preference would be to screw a batten parallel to the crack & run a 6mm spade bit the full length & depth of it, then epoxy glue in a spline.

[Eric D]

I personally would agree with Candy on this, saw, rout a gap, then scarph a new shorter section where the strip is cracked already, then epoxy back in a spline. Carbid tipped blade or router, may ruin it long term, but you have in reality a very small area to do. I have hit steel nails and not much happens....

but, then again....hopefully the real experts will tell you what to do.

I do like that huon...pretty wood.

[Larks]

I'd not considered chopping through the existing nails completely, If I do (and you are right, there are not really all that many, probably eighteen or so - six all the way through, six tips and six ends), do you think I'd then need to re-nail it off again diagonally from the inside? Or do you think the nails are more to hold the strips as they were being glued?

[floatingkiwi]

Why not just rivet a board to the inside of the hull that spans the problem areas? It would eliminate the cutting of any nails, using no glue would allow movement and the whole shooting box would clamp up tight once wet.

[Candyfloss]

Nothing stopping you from skew nailing from the outside & the inside should you feel the need. The nails are there because, with resorcinol, you would not consider not nailing.

[John B]

Biscuit joiner is a great tool for that sort of job. Run it down a batten with a specially made blade or just pass twice. Great depth and location control and tracking, and more robust than some little 5 mm bit in a router. And it clears the waste better.

[Slacko]

If there are only 6 nails all the way through, I would think they are there to hold the planks in place while the glue sets only.
I'd go for routing a groove and put a spline in.

[Phil Y]

Greg I'd cut the gap nice and clean with a circular saw, chop through the nails, and glue in a spline. Huon is very stable so I'd not worry about swelling. An epoxied spline is going to be stronger than the nails. The nails are really pretty well redundant. I would not glass over the repaired section. I have done a couple of those on Balia, much smaller, only about 1 metre-and I did glass because my hull has always been glassed. Same principle though.
Phil

[floatingkiwi]

Personally, I think that to assume the nails are only there to hold things together until the glue set, is a mistake.
Have you tried to remove any of those nails? They are tough as all hell to get them out, short of destroying the wood. I took a whole hull apart and separated all the mahogany strips and kept all the ribbed copper nails for elsewhere and sure there was a little glue between each strip, and if those nails hadn't been in there, (same nailing pattern as you describe there Greg), the structure would have caved in long before I ever got to it. I saved two long and wide pieces of that hull and they are now the cabinsides of my folkboat. If the nails weren't in it, unless I had done something like set glass over both sides, they would have been unsuitable and I would not have used them. My opinion.

[Larks]

Thanks for the input guys and thanks for the photos Phil, I have a whole lot more confidence that this is the right thing to do now. I'll do as suggested and cut a nice clean slot of a uniform width the full length of the lower joint split from the transom right through to where it jumps planks and drops back down again, and do similar for the split above it, going about 200mm past the split either side and glue or epoxy in full width splines. I'll also cut out about 100mm of the cracked plank and reglue a piece in place and I reckon I'll probably skew nail down through the strips for good measure, whether they are needed or not they won't do any harm.

I've been sanding back a couple of other areas that looked a bit "suspect" and I can see that there have been a few other sika' repairs at some stage as well, albeit onmly about 200-300mm long and quite well closed at the moment. Although these repairs have obviously worked I reckon once I've done the spline repair on the most troublesome split I'll find it a reasonably simple job to do a proper spline repair on any other of these spots as well.

John, I had thought of the biscuit jointer as the blade is the perfect thickness, but the planks are about 30mm thick so my biscuit joint won't reach all the way through, I think it's max depth is about 15mm or so. But if I use a 25mm/1" long router bit with a 6mm/ 1/4 inch cut, the same as the shank, I'll be able to cut an even slot the full depth with a couple of passes, using a batten screwed to the hull as a guide. It's either that or the circular saw and move the batten to get a second pass about 3mm offset to the first to get two blade widths of cut....

I'll let you know which works the best.............................(which will no doubt be the one that I decide has the least potential to run astray.........I mean the one that has most potential to be accurate)

[shade of knucklehead]

I normally use a router with a quarter inch straight bit to cut through strip planking. If you take very small passes you can not only cut through copper nails, but bronze screws, stainless and monel nails and Iron drifts. The most important thing if you are just doing one pass is to have a batten on each side of the router because nails and screws tend to make the router jump a bit.

[Phil Y]

Greg we cut mine with a hand held circular saw, freehand, no problem at all. I guess you may need a batten for guidance if your crack is wider than the saw blade though. With respect to floatingkiwi's comments-true enough, but your repair will be held together with a good pasting of epoxy-not the odd bit of glue that he has found in his. I'd be perfectly confident of strength without nails (indeed I AM perfectly confident of my repair) on that basis.
Phil

[Duncan Gibbs]

If you do toe nail the splines in, make sure you drill pilot holes.

[PeterSibley]

I'd just cleat them in 'til the glue went off .I'm a rough bugger .

[Candyfloss]

You might want to make a hollow foot for your router, if that's what you end up using. Something so that the router runs on rails & does not wobble on the curved surface of the hull, making a wobbly cut.

[Larks]

You might want to make a hollow foot for your router, if that's what you end up using. Something so that the router runs on rails & does not wobble on the curved surface of the hull, making a wobbly cut.

Bloody good point Graeme and easy enough to do, thanks

[Phil Y]

If you do toe nail the splines in, make sure you drill pilot holes.

Is that what I did? jeez i reckon a bloke could over think this stuff.

[PeterSibley]

Bloody good point Graeme and easy enough to do, thanks

Just 2 outside rails on a wide ply sub base Greg .

[RFNK]

Well, I just caught up with this. It's very relevant to me as the Twister has a splined hull and I'm going to be replacing a whole lot of cracked and split splines and adjacent planks. With yours though, have you considered the possibility that this opening up is worse where it is due to the position of your floors? It's common to see longitudinal splits in old wooden boats due to the opening up of the planks just above the line of the top of the floors. When the boat heels, the weight of the ballast opens up the planking on the windward side. If the wings of the floors aren't staggered in terms of their height, then a crack can open up along the hull. The remedy is to stagger the height of the wings, add a few ring frame-like reinforcements near the mast and directly above the heavier part of the ballast.


As far as filling the gap goes, I'd definitely glue in a spline and, as Phil suggests, I wouldn't bother with edge nails - what would they achieve?. If it's narrow, I'd just glue it in with epoxy. If it's wider, I'd glue it in and run some fasteners through the frames. I wouldn't use a router. I intend to have a splining blade made for a small circular saw. I'll just run that along a batten for the line. To have the splining blade made, I'll take a regular blade to a saw doctor and ask him to weld new shaped tungsten tips to the blade. I just need to give him the depth and angle. In some areas, just one run of the saw should be enough. Where it's wider, I'll have to do adjacent cuts.

I also thinks JB's suggestion of a biscuit joiner is a good one but, I think, only if you can achieve a tapered slot with it. the danger of a straight cut is that you can push all the glue out or through when you push the strip into a straight slot. If you could angle the cutter and do two runs or get a shaped biscuit cutter blade then I think it would be easier to manage than the saw.
Rick

[RFNK]

You might want to make a hollow foot for your router, if that's what you end up using. Something so that the router runs on rails & does not wobble on the curved surface of the hull, making a wobbly cut.

That's a really good suggestion. I'll do that for the base of the little circular saw for the same reason.
Rick

[Larks]

Well, I just caught up with this. It's very relevant to me as the Twister has a splined hull and I'm going to be replacing a whole lot of cracked and split splines and adjacent planks. With yours though, have you considered the possibility that this opening up is worse where it is due to the position of your floors? It's common to see longitudinal splits in old wooden boats due to the opening up of the planks just above the line of the top of the floors. When the boat heels, the weight of the ballast opens up the planking on the windward side. If the wings of the floors aren't staggered in terms of their height, then a crack can open up along the hull. The remedy is to stagger the height of the wings, add a few ring frame-like reinforcements near the mast and directly above the heavier part of the ballast.


As far as filling the gap goes, I'd definitely glue in a spline and, as Phil suggests, I wouldn't bother with edge nails - what would they achieve?. If it's narrow, I'd just glue it in with epoxy. If it's wider, I'd glue it in and run some fasteners through the frames. I wouldn't use a router. I intend to have a splining blade made for a small circular saw. I'll just run that along a batten for the line. To have the splining blade made, I'll take a regular blade to a saw doctor and ask him to weld new shaped tungsten tips to the blade. I just need to give him the depth and angle. In some areas, just one run of the saw should be enough. Where it's wider, I'll have to do adjacent cuts.

I also thinks JB's suggestion of a biscuit joiner is a good one but, I think, only if you can achieve a tapered slot with it. the danger of a straight cut is that you can push all the glue out or through when you push the strip into a straight slot. If you could angle the cutter and do two runs or get a shaped biscuit cutter blade then I think it would be easier to manage than the saw.
Rick

Thanks for the input Rick. The floors were something that I had considered quite a while ago after a comment by, I think, Jay (I don't remember who) - but these openings are well above the floors so I really doubt that they come into play in this problem.

Great idea re the saw doctor though, we have one come around every Wednesday to pick up our meat axe blades and other saw blades for sharpening so I'll hit them up and see what they can do.

[PeterSibley]

I bought a biscuit cutter the other day at Aldi Greg , probably junk but maybe not .A whole $40 ! The blade is about 4.5mm thick IIRC ,it might be a good basis for a ground up job .

[floatingkiwi]

Greg, are you glueing gaps in boards or the gaps between boards?

What Rick said about the floors is exactly what I had. As the hull dried a series of cracks appeared at various places at the floors wing tops, and I fixed them as they appeared. This was on a lapstrake and I repaired individual boards making sure I didn't glue any of them together.I know this isn't really relevant to your cause. I'm just sayin'.

[RFNK]

Thanks for the input Rick. The floors were something that I had considered quite a while ago after a comment by, I think, Jay (I don't remember who) - but these openings are well above the floors so I really doubt that they come into play in this problem.

Great idea re the saw doctor though, we have one come around every Wednesday to pick up our meat axe blades and other saw blades for sharpening so I'll hit them up and see what they can do.

I'd be interested to hear what your saw doctor says. If it's too expensive, please let me know and perhaps we'll be able to share the cost or something. I'd be happy to pay the lion's share as I'll be doing a lot of work with this blade but it'll be a year or two at least before I get to fixing up the planking. I have a shed to complete and a whole lot of renovations to get into before I'll be able to gt back to the boat. And of course work gets in the way a bit!
Rick

[John B]

I've never felt happy about that wedge spline idea, an orange pip squeezed out between your fingers springs to mind.
I just don't see the issue, you square spline with some glue clearance, you wet out properly, you run the squeezeout along the spline as you're knocking it in. I have limited hands on experience doing it but the splines I fitted 20 years ago are still there and they were trouble free up to 08 when I pulled the boat..

[Larks]

What do you guys think of perhaps stacking a couple of blades as a dado set up to get the width on that wider gap?

Like this but on the hand saw:

[RFNK]

I've never felt happy about that wedge spline idea, an orange pip squeezed out between your fingers springs to mind.
I just don't see the issue, you square spline with some glue clearance, you wet out properly, you run the squeezeout along the spline as you're knocking it in. I have limited hands on experience doing it but the splines I fitted 20 years ago are still there and they were trouble free up to 08 when I pulled the boat..

You might be right there John but I think a big advantage of the wedge shaped spline is that it's a more tolerant arrangement - the glue can't be squeezed out. When fitting a long spline, the spline may not want to follow the curve, the cuts may not be quite square etc. With the wedge, the glue is captured regardless, so I think there's a reduced chance of voids or dry areas. I can't see splines which are epoxied in being squeezed out.

On the other hand, it may just be a hangover from the resorcinol days when ample gluing pressure was needed for the glue to be effective - hard to achieve that with a square slot and avoid dry patches.
Rick

[Larks]

Rick, do you have any sort of idea what width and angle you're thinking of for your splines? I'll admit that, despite all of the great advice and ideas here, I'm still a little undecided as to how to cut mine yet, but I'll talk to the saw guys tomorrow to see what they can do and I reckon I'll try a couple of methods on a mock up before I take to the hull in anger with any weapons.

I'm still thinking I'd be best to screw on a guide strip, rather than free hand like yours Phil, simply because of the length and curve of the hull and strips. And if I do go with the single normal saw blade idea I reckon I'd run a straight cut then move the guide strip 4mm and do a second cut with the blade angled only very slightly to create a very mild wedge shape to the spline. I do also like the idea of a slight shape to any spline or hull repair piece simply because it's more likely to be pushed in than out by water pressure on the hull.

[rlaggren]

Wonderful thread. Thanks for sharing, best luck w/your project.

> open glue line...

Two thoughts:
- The tool of choice may be determined by your working position and hence you ability to control the tool.
- If favoring a router (I think I would) you may find it worth while to get a custom bit made to your specs. Or if you talk with the right people you might find one already is out there. I'm thinking along the lines of a chamfer or cone bit very skinny, long and pointy; the angle between the center line of the bit and the cone would be very small - maybe 5d (or less) and the length of the taper would be (say) 1-1/2"; not sure how long a bit they would allow you with a 1/4" shank, though. Here are a couple of quick google results that might have the knowledge you need:

http://www.vexorcwt.com/router-bits.htm
http://www.toolstoday.com/c-434-custom-router-bits.aspx

(this one has a "call us" button - but don't know if they can help)
http://www.heleta.com/carbide-produc...orLanding/true

> rounding over edges...

Yes, yes, yes. And I agree the fact you couldn't run the bit fully into the corner resulted in a great appearance. However, should you wish to get close into the corners, a good laminate router with and offset bit kit can get you within about an inch.

Cheers,

Rufus

[shade of knucklehead]

I just read through you options again, and I think I like Option number 1 with thickened epoxy. I don't see anything wrong with that. It leaves the existing strips alone, it leaves the fasteners that are in there alone, and it fills the void with matching wood...

[RFNK]

Greg, I'd guess that the splints I'll use will be about 8mm at the face edge, 4mm at inside edge and about 20mm deep. I haven't measured it though so that's only rough. Rick

[Duncan Gibbs]

Old boatbuilding guy with 40+ years doing the wedge thang on his new project.

[Larks]

Thanks for the great links Rufus, there are a few bits there that I've never seen before, very interesting!!

Rick, I haven't seen the guys come around today but I will certainly be bending their ear when they come in and seeing what they can do and how good a price they can do it for!!!


Thanks for the input Knucko', I'll include that in the experiment options before committing, I'm not sure whether any are easier than the other as I still need to clean the glue line out but this option does seem to be one of the easier ones.

It'd be so nice to be doing this on a new hull Duncan, at least I'd have the planks shaped before hand and wouldn't have the old glue to contend with. Great photo though - have you posted that before? It looks familiar.