variation in strip thickness

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MFriendly
Posts: 8
Joined: Mon Nov 19, 2012 11:19 am

variation in strip thickness

Post by MFriendly »

Hello -- -I am a new builder.. of a Resolute kayak. Appreciate all the knowledge here!

I apologize if this has been addressed somewhere, but I could not find the answer. I have been ripping 18' strips of clear cedar on my table saw (11/16" wide) to just over 0.25" thick. There is of course, some variation in the thickness of the strips. Most are between 0.255" and 0.260" as measured with digital calipers, which I am happy with. However, some get thinner at some places on the strip (down to 0.235" or so at times). I plan to cut those pieces out if necessary and use the shorter strips as butt-joints, or in places where a long strip isn't needed. My question relates to how much variation in thickness is allowed before problems occur (extra sanding to smooth hull, problems with thin beads breaking away).

I found one reference on another web site that strips should be the target thickness "plus or minus a few thousandths". How much is a "few"?? Should I cut out and discard potential problem areas first, or just mill them on the router "as is", and cut away bits later if the bead looks poor?

Big thanks in advance. I am sure this is the first of many questions!
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Patricks Dad
Posts: 1476
Joined: Wed Oct 13, 2004 1:11 pm
Location: Warrenville, Illinois

Re: variation in strip thickness

Post by Patricks Dad »

25-30 mils narrower than your thickest strips seems a bit big to me. But, if you put a thin strip next to another strip that isn't of your max thickness, you won't notice the difference as much when you plane/sand to fair the hull. I would mill the bead/cove on them and see how they look. There will be LOTs of places where you won't need a full strip if you decide not to use them as is. Some guys build entire boats with 3/16" thick strips so you shouldn't worry about the thin strips being too weak.
Randy Pfeifer
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HighPlainsDrifter
Posts: 77
Joined: Tue Mar 22, 2011 9:30 pm
Location: Brookings, SD USA

Re: variation in strip thickness

Post by HighPlainsDrifter »

You will have a headache trying to bead and cove strips that are of different thickness (voice of experience)........ and if you manage to bead and cove, you will end up with another headache trying to plank up the hull with different thickness strips.

I would (and have done just that) run the batch through a surface planer before bead and cove. You will end up with a quality batch of wood and you will have the added benefit of getting rid of any saw marks on the wood.
BearLeeAlive
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Joined: Tue Aug 18, 2009 7:00 pm

Re: variation in strip thickness

Post by BearLeeAlive »

One thing you can do if the bead and cove is not cut yet, is to decide beforehand what side will be on the inside of the hull and mark this. If you then mill all your strips with this side down, they will fit nice on the moulds, with all the variations on the outside. This would be relatively easy to fair smooth later, at least way easier than the inside.

But, like HPD said, if you have access to a planer, just take them all down to a uniform thickness, even if it is a fair few thousandth's below 0.25.
-JIM-
MFriendly
Posts: 8
Joined: Mon Nov 19, 2012 11:19 am

Re: variation in strip thickness

Post by MFriendly »

Thanks guys for your help. I have taken the advice here, and planed the planks to uniform thickness. All are now a tiny bit shy of 1/4".... generally between 0.243 and 0.248. I think I can live with that. If there are any problems with the variation I will find out when I mill the bead and cove on them (next step). The first batch of strips I ripped were about 0.26", but with lots of wobble, so I had to plane them a bit thin to salvage as much as I could. Still, there are saw marks in some places, but planing any thinner may have caused me more grief in the end. The second batch I ripped to about 0.3", and planed from there. Ended up with some very nice strips.. no saw marks.

Oh yes... it was not a cheap solution.... $650 for a DeWalt planer, and $300 for a dust collector. I suppose in the end I should have just bought strips and saved some money. But every project is a chance to buy a new tool that will add to my collection. I think a planer is a great investment, and a dust collector is years overdue.

The first of many lessons learned!
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