Strip planking newbie question

Why is bead and cove expensive? Is that based on an assumption that bead and cove strips would need to be purchased with bead and cove machined? It would seem to me that if the builder can machine the bead and cove themselves than the added expense is the time needed. Epoxy filler isn't free, and beveling strips takes time.

 

For a home builder machining the plank stock is expensive. If you already have the fixed machinery...planer, shaper... in your shop then its a the labour saving hence cheapest way to go.

One detail of strip plank that's troublesome is finishing the inside of the planking. If you want a " Finished interior" you must use cove or tonge and groove stock. Square edge stock leaves a very rough , glue stained interior finish

 

Or tongue & groove with the corners knocked off......

 

A router mounted in a simpler router table (sheet of plywood with a clamped board for a fence) and a pair of matching router bits should be sufficient up to 1" thick planking. Thicker planking might require two passes.

 

Sure, not difficult to machine stock. But remember many home builders are literally building a canoe or whatever in their living room. Takes shop space and machinery to mill timber.

One of the reasons plywood construction is so popular with homebuilders is that you don't need any woodworking machines.

By all mean when building a strip planked boat choose milled, cove or tongue and groove timber . It really saves and produces a better product.

 

When working at Mystic Seaport I got to closely examine some very early (1870s) strip built 24' sailing fish boats of fairly radical curved shapes, and the strips were beveled since they did not have epoxy fillers, but not done with the obsessive exactitude and unnecessary machinists' precision seen in amateur builds. These boats were made with 7/8" square scraps from a local box factory and have held up well. No glue, just nailed strips with not many frames. They may have put white lead paint between, I don't know, but I doubt it. Only one edge of each strip is beveled as needed.
In the early 70s two of us did a total replank on a ten year old, 39' strip-built ketch which had leaks, gaps and poor fits throughout. We used Honduras 1 1/8" x 2 1/8" bead and cove, bronze screwed to frames and edge-nailed between, with Weldwood glue and dead on fits. Started at the keel ripping off old plank and building new and kept going up till we got to the sound deck and toe rail without disturbing the very very nice interior, put the overhauled masts back in and went sailing. Some strips we tapered, then re-contoured one edge, the convex one, with a molding hand plane on the bench. It was a fussy job that took a month but gave a nice hull when we were done that we were proud of. It was not sheathed, just a good paint job.
The modern way of more and more goop and filler I think is not so good, but does the job, is quick and easy, and good enough if you sheath it, especially in very small craft of under 1 ton.
The above poster is right about slippery strips crawling around because of the bevel, but tapping a very small copper tack half way into the in-place strip, nipping it off 1/8" above the surface, then pressing the new strip in place will cure this in the few places it's actually a problem. If the hull is fair, the strips should behave if the lining-off is right. If you are trying to twist and bend them too much, they can be a problem. If lined right, it's almost all bend with little twist, and they lay right down. This is usually not what the sheer demands, since the planks would all run off at the top, so occasional tapered planks will usually give an acceptable compromise between good lining and good looks.
And I am a fan of beveling strips or bead and cove, having done both.

 

When filling in the gaps if you used square cut strips, would you be able to fill them with just clear epoxy? Does epoxy dry clear or does it have a slight tinge?

Thanks everyone so much,

Jordie

 

Clear straight epoxy resin would be too thin and would run out. Use WEST System "filleting compound" mixed in till it's like mayonnaise.

 

Bead and cove is expensive if you buy it and expensive in time if you do it yourself. Also, it still produces a hull with small flats that has to be faired. Worse, when you fair the hull, the thin edges get cut unevenly and the lines are crooked. Bevelling planks takes very little time.

 

Generally the less complicated treatment the strip edges receive the easier it is for the home builder. However as noted above square-edged strips need filling which uses a lot of (expensive) epoxy and other glues are not gap-filling. My own preference is to bevel the strips, which is simple to do.

It pays to check the design carefully - sometimes you get lucky. On my last boat, due to the design of the boat the bevel angle was the same for most of the strips and constant along their entire length. This allowed me to cut those strips with identical bevels. The strip was beveled while it was still on the plank with a table router then the strip was ripped and thickness planed.

However, for most hull designs the bevel will vary along the length of the strip and from strip to strip. It is convenient to cut a rabbet to fit a single strip in the edge of a long plank. Mount it in a vise and block off one end, then insert the strip and plane the edge of the strip. It only takes a couple of passes with the plane to get it close enough first time - once you get a feel for it.

From my own experience, try to keep glue cleaned off the inside of the hull as you go, if possible, since it is a lot harder to sand the inside of the hull than the outside - where a random orbit sander can be used.

 

Not if your spacing is correct
I used a paint scrapper for my plank spacing and then rolled epoxy in, followed up with a squeegee
Resin came through to the other side and those spots that didnt, got backfilled when the resin was green

Larger gaps had a low density filler added

This was far quicker than gluing individual planks and allowed me to build a 50fter by myself.

 

guys,
fully agreed with sabahcat, I even do a little bevel outside to be sure the resin go through and all strip are just in contact inside, it's a dry and clean work to pre-install on the jig with screw, when done, put your gloves, and squeeze the liquid resin with paint scrapper, push the resin with resin+ filler is gap larger, until you see the resin inside . when the resin is cured, remove the screws, fill the remaining , take only few day to cover a 50ft hull !
all cut out show 100% of the V gap is filled/glued.
pict on www.fusionschooner.blogspot.com
have fun !
all the best !
bertho

 

For my next stripper I plan to use regular square edged strips, assemble the strips on the mold dry, then fill the gaps with thickened epoxy. Although the seams will show in a bright finished hull they will be even width and may make an attractive contrast with the planking or even look like grain between the WRC strips.

The cost of epoxy was mentioned as a consideration in an earlier post but very little is needed. For example to cover both sides of a 15' canoe from keel to sheer with 3/16" strips, the gaps are equivalent to two 3/16" radius quarter-circle fillets 15' long. This works out to the contents of one of the self-mixing cartridges of pre-thickened epoxy from System 3 or West System. Not enough for the entire boat of course but I can use ordinary epoxy elsewhere.

I have used these cartridges before and they deliver a well-mixed non-drip compound. West System claims a characteristic called shear thinning eliminates the need for wet-out with thin epoxy. If I find the cartridge and caulking gun are a bit clumsy for such fine work then I will use it to fill a hypodermic. Less waste, less cleanup. I may need to use thinner epoxy for narrow gaps.

 

Sounds like hard work

Doing it how I mentioned above, most resin pulled through by capillary

Wastage was minimal, I estimate less than 4 litres (more like 2) of resin dripped on the floor from 2 x 50 ft hulls or 3600 lineal metres of seam

 

Beveling square edged strips is easy and fast, plus you don't have to spend a day or two at the saw, making saw dust out of 20% of your stock, just for coves. A hand plane and a few swipes and you're good to go. At the turn of the bilge, you'll have more plane work, but it's fast, easy and very little waste. This is the traditional way, but modern methods can't beat it in terms of speed and waste. If you plan on using epoxy, then your bevels don't have to be perfect, though some minor seam differences will show.