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View Full Version : remove plank on glued lap build?



Falcon1
09-11-2016, 09:20 AM
So I've had to admit that my Ilur build is not going as smoothly as my last build, which was also glued lap.
Until this morning, however, I thought I was doing ok, just a little messy. Now I may have to remove a plank.

The problem is up near the bow at station 9. The last planks were lifting off the molds a bit there, but were at least the same-as in symmetrical. The third plank on the port side was about 1/4 inch off the mold (first photo.) This, I could live with, I thought, but the third plank on starboard, which I glued on yesterday is out about 3/8ths more than that, for a total of about 5/8" out. (Second photo) It's apparent from afar, and I realize that I should have been bringing planks tight to molds all along. I will from here on out. I also don't a want this mistake to be cumulative, so am faced with a dilemma.

My first thought was to leave it glued, and basically fudge it. Bevel this plank over-much to get next plank to go where it needs to be, and continue on, but doing it right from now on. I think there's enough meat on these planks to do so.

Second choice, use a heat gun to undo about the forward third of this plank, clean it up and re-do it correctly.

Third, use heat gun, remove plank entirely and try again. (I fear this is what you all will tell me to do!:d)

How hard is it to get a plank off? What is the best course?

Thanks, Mike

https://c7.staticflickr.com/9/8234/29495334222_448ab1b784_b.jpg (https://flic.kr/p/LWpigd)IMG_0523 (https://flic.kr/p/LWpigd) by Michael Owen (https://www.flickr.com/photos/107084128@N08/), on Flickr

https://c1.staticflickr.com/9/8477/29495333952_230dac41cd_b.jpg (https://flic.kr/p/LWpiby)IMG_0524 (https://flic.kr/p/LWpiby) by Michael Owen (https://www.flickr.com/photos/107084128@N08/), on Flickr

https://c5.staticflickr.com/9/8541/29571120356_6bb10f8e6c_b.jpg (https://flic.kr/p/M46HQG)IMG_0522 (https://flic.kr/p/M46HQG) by Michael Owen (https://www.flickr.com/photos/107084128@N08/), on Flickr

jackster
09-11-2016, 10:28 AM
Mike...Mike...Mike... Your first mistake is letting ANYONE know that what you did was not thoroughly intentional!!!
Now, we must chide and denigrate, 'cause that's what we do. (sigh) Cinch up those big-boy pants!!
Are these planks spiled or cut to a pattern!
Did you indeed not bring the planks to their marks-notches!
Are the lap overlaps to specs!
Are the laps a fair curve!
Are the hood-ends (and transom ends) on their marks!
Did you screw-up the molds!
All those questions are to identify the problem.
Whatever the answers, what I would do is spile the next(#4) plank to straighten everything out and pay more attention to how things align from now on!
That's my take, anyway. Keep up the good work:) Cheers

Peerie Maa
09-11-2016, 10:40 AM
So I've had to admit that my Ilur build is not going as smoothly as my last build, which was also glued lap.
Until this morning, however, I thought I was doing ok, just a little messy. Now I may have to remove a plank.

The problem is up near the bow at station 9. The last planks were lifting off the molds a bit there, but were at least the same-as in symmetrical. The third plank on the port side was about 1/4 inch off the mold (first photo.) This, I could live with, I thought, but the third plank on starboard, which I glued on yesterday is out about 3/8ths more than that, for a total of about 5/8" out. (Second photo) It's apparent from afar, and I realize that I should have been bringing planks tight to molds all along. I will from here on out. I also don't a want this mistake to be cumulative, so am faced with a dilemma.

My first thought was to leave it glued, and basically fudge it. Bevel this plank over-much to get next plank to go where it needs to be, and continue on, but doing it right from now on. I think there's enough meat on these planks to do so.

Second choice, use a heat gun to undo about the forward third of this plank, clean it up and re-do it correctly.

Third, use heat gun, remove plank entirely and try again. (I fear this is what you all will tell me to do!:d)

How hard is it to get a plank off? What is the best course?

Thanks, Mike



https://c1.staticflickr.com/9/8477/29495333952_230dac41cd_b.jpg (https://flic.kr/p/LWpiby)IMG_0524 (https://flic.kr/p/LWpiby) by Michael Owen (https://www.flickr.com/photos/107084128@N08/), on Flickr

https://c5.staticflickr.com/9/8541/29571120356_6bb10f8e6c_b.jpg (https://flic.kr/p/M46HQG)IMG_0522 (https://flic.kr/p/M46HQG) by Michael Owen (https://www.flickr.com/photos/107084128@N08/), on Flickr

On first reading I thought that you meant the plank was standing off the mould making the boat fatter, but I see that is not the issue.
I notice that the gains are very wide on the stem, are they meant to be that big?
If you hang the next plank to its marks, how wide will the lap be? If there is adequate glue area I would just carry on.

Gerarddm
09-11-2016, 11:08 AM
Is the rest of the plank seated properly? You MAY get the first third of the plank undone to try it again, but I would be concerned with edge setting.

That's a big gap. I would heat gun the whole thing and retry were it my boat. Recheck your spiling while you are at it.

Falcon1
09-11-2016, 11:18 AM
Thanks for the quick replies, folks.

The planks are cut to a pattern, as are the joggled moulds. My last build had no joggles, and I spiled each plank. I think this made for a better system, at least for me.

Nick, the plank is standing off the mold, making the boat a bit fatter on starboard. Sorry the photos don't show it very well.

Gerard, the edge-set problem is worth thinking about for sure.

Anybody remove a glued plank before?

Rich Jones
09-11-2016, 12:41 PM
I made a mistake a few builds ago and had to remove a plank. A heat gun and putty knife did the trick although I did scorch the plank a bit. This was 4mm ply. I believe yours is much thicker, so don't know what results you'd get.

Peerie Maa
09-11-2016, 12:53 PM
May be heating the putty knife as well?

Falcon1
09-11-2016, 02:13 PM
Following John H's advice, I tacked a batten to check the molds. All seems ok with them.

On my last build, I had a spot where, if I brought the plank down to the mold exactly, it resulted in an unfair line at the lap. I left it floating a bit off the mold, achieving a fair line and it turned out ok.

I think this experience influenced me too much as I began planking this boat.

Still trying to decide what to do...:confused:

Mike

https://c1.staticflickr.com/9/8435/28986367664_cc5641dbf2_b.jpg (https://flic.kr/p/LaqHeJ)IMG_0525 (https://flic.kr/p/LaqHeJ) by Michael Owen (https://www.flickr.com/photos/107084128@N08/), on Flickr

https://c7.staticflickr.com/9/8139/29501904222_63b09b155b_b.jpg (https://flic.kr/p/LWYYi5)IMG_0526 (https://flic.kr/p/LWYYi5) by Michael Owen (https://www.flickr.com/photos/107084128@N08/), on Flickr

Peerie Maa
09-11-2016, 02:17 PM
I still think that those laps at the stem are wide, and advise checking them out.

John hartmann
09-11-2016, 03:04 PM
I agree with Peerie Ma about looking into the width of the gains.....I went back through my build photos, and found an image from the stern that shows a gain clearly--my recollection is that those were pretty consistent throughout the build.....the pencil line in your photo above looks considerably greater, although perspective can be deceiving......sorry I couldn't find an image showing gains at the stem......

http://i1166.photobucket.com/albums/q617/JohnHartmann/ilur%20build/image_zps2b524542.jpg

Falcon1
09-11-2016, 04:16 PM
The plank laps have all been 7/8" wide, and the gains are more or less the same. I've been doing the half-lap gains, and have found them a little tricky, but I like that there is plenty of wood at the ends as opposed to a feather edge. 7/8" seems to work well, the plank edges land where they should on the molds.

The fault seems to be in the above-mentioned false thinking, and a tad of impatience. All dry-fits from here on out will be patiently fitted until perfect!

Phil Y
09-11-2016, 05:09 PM
I think you can just fix it over the next 2 or 3 planks. Don't try to do it all at once.

andrewpatrol
09-11-2016, 07:28 PM
Mike, a fair line RULES. If you made them fit to mould what would it look like? Planks look nice, dunno that I'd be redoing it. My boats planks sat off the first mould too ( apparently it's quite common) and they came good as I got further up the hull. Dunno what causes it but like Phil said just ease them back into line as you proceed. Not all at once.

nedL
09-11-2016, 09:25 PM
I would look at the planked boat and decide if she looks fair, and if I like the lining off of the planks. If happy, I would just continue on.
Of coarse I tend to think that people building boats today get hung up on a 1/4" here or 3/8" there to much. Boat duilders on the Jersey shore would use 4 molds for boats more than 30ft long, and in one photo I have I can see a good couple of inches between the planks and one of the molds.

If she looks nice what else can you ask for?

Max F
09-12-2016, 12:47 AM
I guess this depends most of all, if you can live with that?
Probably no one else will see it.
If it disturbs you too much, now is the time to cut it out and redo it to make you happy.
In that case, I would cut of as much as possible with a jig saw, peel of the rest with a chisel and finish with a scraper and heat gun.
That is surprising quick work.
Max

davebrown
09-12-2016, 01:57 AM
I agree with the remark that fair lines are more important than exactitude to plan dimensions. Looks like it can be slightly corrected with each succeeding plank. If not, you can replank it. I always think about how one half a Saturday will allow me to correct an error, which is different than perhaps hundreds of trips where I notice an error.

skaraborgcraft
09-12-2016, 04:20 AM
Looks kind of fair from here. I would adjust from here on up as you need to. As mentioned if you have a fair batten sweep then i would have no issue with it. Of course, if it going to drive you batty everytime you look at it, then removal is the only way. I have seen people rip of planks that looked perfectly fair to my eye, and planks that they would never see while sailing...do you want an object of art or a functional boat?

Eric Hvalsoe
09-12-2016, 12:59 PM
If one plank suddenly makes a big jump off the mold, I might redo. If you have gradually worked away, you will want to gradually work back towards the mold with succeeding planks as suggested. Given that you are using plank patterns its hard to say exactly how well that will go, but you want a fair section shape as well as fair plank lines. Presumably you are sure everything else, molds etc, are lined up correctly.

Lapstrake planking does tend to float off the end molds, and this phenomena will compound itself. I have in mind round bottom lapstrake with numerous strakes. I believe this occurs because the gains induce a twist which lifts the plank edge off the mold. For that reason I edgeset my spiling batten a wee bit between the last mold either end, and the bow and stern of the boat. This counteracts the tendency of the plank to lift. Even then I usually tolerate a little bit of 'growth' at the ends. Clamping the plank to the molds as they are nailed or the glue sets is helpful. Once lifting occurs you are in a sense redesigning the boat, and you should keep in mind the fair line, mold or plank. Also keep in mind port and starboard symmetry.

Using pre-existing patterns, you don't have the option of edgesetting a spiling batten. If the boat was designed and patterns generated on a computer, it would be interesting to know if the computer or the operator is as cagey as a veteran boatbuilder in this regard.
Eric

FYI - I take the lap down to a feather edge (or a feather corner at the transom radius), cedar or plywood. In my experience it presents no weakness or problem, and involves a little less fussing.

nedL
09-12-2016, 05:46 PM
Take a look at that one mold with no planks touching by what looks like a good inch or so.

https://im1.shutterfly.com/media/47a2d704b3127ccef1664b7a577a00000030O02Bbs3DVuzZA9 vPhI/cC/f%3D0/ls%3D00200375837020120925184446595.JPG/ps%3D50/r%3D0/rx%3D550/ry%3D400/

stromborg
09-13-2016, 03:31 PM
A couple of thoughts come to mind here

Pattern issues: What are they made of? I would have a difficult time trusting a piece of paper as long and skinny as it would have to be for a plank on this boat. Are you marking out one plank and using it to pattern the other? At least then you know they are symmetrical.

Gains: Are the patterns laid out for a half lap or feathered edge gain? Is the length specified? Both of those wil effect the amount of twist you have to put in (by a surprising amount as I discovered the hard way at one point)

Heat gun-vs-already glued joint: Harder than you might think to heat up the underlying epoxy enough to release
https://photos.smugmug.com/Boats/Deer-Isle-Koster/KDI/i-nqgPQXb/0/M/2012%2010%2016%20002-M.jpg
I decided to shorten these Pete Culler-style oars after using them for a while. it took a really long time and I scorched the 3/16" thick plywood pretty well before the epoxy finally released. Wood makes a good insulator!

What to do now?

I'd take good hard look at tweaking the two sides until they were both fair and consistent (out with one in with the other) and spile from there, now that you are off the molds the patterns are also going to be off until you get the planks back down on the lands.

WoodyHuscarl
09-13-2016, 04:24 PM
[QUOTE=stromborg;5004581]

Heat gun-vs-already glued joint: Harder than you might think to heat up the underlying epoxy enough to release

QUOTE]

That's why I think buying a couple-three sacrificial putty knives might be in order. You can use the heat gun to bring them to temperature, then use one until it cools, and switch out as needed.

Falcon1
09-13-2016, 08:08 PM
Thanks again for all the thoughtful replies! I believe I'm going to leave the plank on and try to get back to the molds over the next two or three planks.

I've inserted a small shim on the mold on the "other" side to try to push that plank out a bit in the same spot as my problem. Symmetry rules!
I also attached beveled poplar blocks to the molds a bit proud of where the planks should land and will try screwing the next plank to that, then a bit less proud on the next pair of planks, and finally back to the actual mold on the 6th pair.

Thanks so much for the encouragement. I'm not looking for a bright-finished work of art, but I do want to do the designer justice and have a functional vessel at the end.

Mike