Plywood Scarfs and How Many Sheets

After a bit of practice in scarfing I think I can do it.  The wood should be here late in the week.

 

I am building a 16 ft high side drifter from Don Hill's plans. 

 

I am wondering how many 8ft sheets do I need to scarf to go the full 16 for the length.  I am okay if the boat ends up a bit shorter than 16ft.  I was planning to buy four 1/4 sheets for the sides and scarf 2 together to get the length but I then saw something that made me think I should do 3 and have two joints on each side.

Thoughts and explanations would be awesome.

 

Cheers

Dano

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Permalink Reply by Lawrence E. Long on April 4, 2011 at 8:34am

Dano:

Call Don Hill and see what he says.  If you really need a full 16' you cant't get that out of 2- 8' sheets as you will loose 2-3 inches per scarf- depends on the PW thickness abd what slope on the scarf- 8/1 ,10/1, or 12/1.  Also you might "screw up" a scarf and have to do it over.  Might I suggest you get  an "extra" sheet or so of PW and have 2 scarfs on each side. This is the way the 17' Obrien worked out built some years ago.  Scarf on sections of the 8'sheet in the middle to both ends so you end up with a sheet  with 2- 5' ends scarfed to the middle sheet giving you around 17-18 ft total.  (Check my math)

 Or- make the sheet 16' (less the scarf) and end up with a little shorter boat.  Some here on the forum have done exactly that. Just one mans opinion- others will chime in.

Good Luck

Permalink Reply by Randy Dersham on April 4, 2011 at 11:34am

Don is unfortunately not healthy enough to answer your questions but I think if you call the number on the website someone will help you.

 

You will need a second scarf to get the extra length but you do not need extra plywood.  You can scarf your plywood to 15.5 ft. and cut out your side panels leaving the tip of the transom end missing on each side panel.  Then you can use the triangle of scrap cut from the stem end to scarf onto the side panel to complete the tip of the transom end of the side panel. 

You will also have a set of 16ft low side panels from the off cuts.  You might need to make two boats!

Permalink Reply by Lawrence E. Long on April 4, 2011 at 3:50pm
Randy:  Looks like you are familiar with the highside Hill plan- and a crafty user of materials.  As a matter I don't throw away any small scraps - and sometimes find a use for them on a subsequent boat .Currently using trimmings  from 2 boats back on a peapod.
Permalink Reply by Daniel Martin Romano on April 4, 2011 at 5:40pm

Thanks for the help.  I plan to use the extra plywood to make a smaller boat eventually.  The kids at my high school are super interested to make a boat and auction it off as a fundraiser.  I will do 2 scarfs on the middle sheet as suggested by Randy.

 

Thanks

Permalink Reply by Dave Z on April 6, 2011 at 4:40pm

I think i have documented somewhere the transom adjustment for a don hill 16 footer with a 15'8" side panel.  This would be just 1 scarf for two 8 ft sheets.  There's an easy way to do this yourself too.

 

Don't build the transom.  Scarf two sheets 8:1 and end up with a 15' 8" side panel.  Cut it out normally,  go build the boat without a transom.  prop it up, level it out, and strap the ends of the boat to make it "look right."  talk measurements, make a fake plywood cutout of scrap and prop it into place and cipher a bit to make sure it "looks right"  capture all your angles, and go make the real thing.  viola,  no problem.    You won't miss the missing 4 inches.  Good luck!  I'm sure the originals were built in a somewhat similar fashion.

Permalink Reply by Randy Dersham on April 7, 2011 at 2:54pm

Dave, the original boats were not built in a similar fashion. Many of the original boats were made from panels that are a full 14ft and then later a full16 ft.  Up until glue joints became just too poor to put up with (just a few years ago)  true 16ft panels were available in Doug-fir from Oregon pro lumber dealers. That is why Roger's book shows the sides cut from a true 16ft panel.

 

I do agree with your assessment of not missing the four inches if a builder chooses to use a shorter panel.  I think it's actually easier to do two more scarfs than it is to measure and create a new transom but that depends on how comfortable the builder is with either scarfs or figuring out new measurements.

Permalink Reply by Dave Z on April 7, 2011 at 4:14pm

Randy,

 

How were the "first offs" of many of the original boats made?  What I meant was I'm sure many of the original first off boats were not precise to any plan and were adjusted in the manner I described.  Or do I have it all wrong, do you think they were modeled to some precision first?

 

 

Permalink Reply by Daniel Martin Romano on April 7, 2011 at 5:03pm

i don't really care either way i think on this boat i am going to do the full 16.  throwing in three more pieces of ply (one for the bottom 1 for each of the sides) won't bust the budget. 

 

If anyone is selling a trailer only that would be sweet even though i think this boat will fit in the back of my truck.  I would love to hear of any used trailers for sale.

 

Cheers

Dano

Permalink Reply by Randy Dersham on April 7, 2011 at 10:48pm

ohhhh, no.

I thought you meant that the original boats were made with a single scarf and three inches shorter than sixteen feet. That's my bad, I misunderstood you.

 

I believe that they had an idea of what they wanted the boat to end up like and then "listened to the wood" in the same way that Brad Dimock talks about.  In many cases that also meant getting the most out of any piece that they could, so in some cases the dimensions of the available materials made a big impact on the final boat.

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