A friend’s father was a master mechanic and machinist. When he did carpentry, he minimum standard was “repeatable 32mm .” I always keep that in the back of my mind, because the front is way to busy trying to make things wok out. Thanks for another good episode.
Great tip on Volume vs. Weight! I've also heard that a piece of fine fishing line in the joint will prevent starving the joint for adhesive. Never tried it for myself, though.
Great, always thought 1:1 was odd but figured that West had developed it that way. Please can you show an easy means to scarf an exising plank on a boat, where section needs to be replaced.
I don’t know about an “easy” means. Every situation demands a slightly different approach. I’ll happily make a video about that when I next have the opportunity. I haven’t had much repair work lately though.
Great video! I just discovered your channel but it it makes me want to try making a boat. I found drawings of the gislinge boat that I might try out if I can fit it in my shop.
Do you ever use a high ratio scarf, then invert the planks to give a slight angle to the finished stock? I'm thinking for the purpose of helping to create when bending may not be a possibility. Then soften the angle to create a radiused bend as opposed to a sharp angle. Not sure if it's structurally unsound that way. Obviously my scarfing is for banjo making applications where the tension put on the joint is far less than with boats. Great video by the way. You seem be a natural teacher.
@@Nomadboatbuilding I guess imagine a slightly bent piece of wood with a large radius, like would be seen where the sides of the hull curve to the bow. Now imagine it isn't one piece of wood, but two scarfed together. Would that be accomplished by bending the piece after the scarf joint is made or would you "help" the curve by flipping the scarf joint to create an angle greater that zero degrees at the scarf? I'm only just curious so ignore this if it makes no sense. Haha.
@@LowlyMountainBanjos okay, I think I get you. I use a technique like that on one piece banjo pots. I scarf the outside face of the inner end and let the outer wrap over that, then after gluing trim the tail end to the pot radius. We wouldn’t do that in boats. We pretty much always just lay out a scarf so the plank is flat in its unbent state and usually shoot for a longer scarf wherever a short one might not have the strength to take a bend. There is one scenario in traditional lapstrake planking where I make the two pieces purposefully unequal and the outer one is faired off as you described.
Thank you for the weight vs volume ratios. I’ve been doing the same 😢 West Systems should update their documentation, as the 105 epoxy system is 1:1 by weight or volume, and I daresay many of us have made the same assumption.
Careful. You mean 1:5. And actually, I vaguely recall reading that it is a little different on that one too. I don’t weigh out the 105. I can never do the math right.
My father always said 8:1 was minimum, as the architectural pedant he was, I tend to believe him. I even maintain this when scarfing skirting boards. I use sandvik saw steel for scrapers, seems to work !
Longer is always better for sure but I have used 6:1 very successfully many times. Of course context is everything. I wouldn’t scarf an unsupported beam that short.
@@cloudymeowsgames7855 well, I learned the 6:1 from a seasoned boatbuilder and it has never let me down for epoxy glued construction. I mostly just use that for scarfing plywood though. Anything else and I usually jump up to the 12:1.
How do you position the scarf joints as far as the boards running lengthwise down the boat? I would imagine you would try and keep them far apart. If one was to build a boat that required longer boards than a person could buy, would it be best to try and make the joints fall as far apart on the hull as possible?
It’s common practice to stagger scarf joints approximately 2’-4’ apart, however I have found that epoxy glued scarfs are stronger than the unscarfed sections of planking so I don’t think there is much concern in placing them even in the same plane. For looks though, spreading them out is a better practice. If you are using plywood planks that are say 15’ long or so, you would make up some planking stock with the scarf in the middle, and then cut a sheet of ply in half and scarf the pieces to either end of a full sheet. Then you would use one batch on one plank and switch for the next to stagger the scarfs. There are different rules for traditional solid wood planking. Two frame bays between joints on adjacent planks and two planks between joints within one frame bay. Joints usually being butt joints but same rules for scarfs which would be mechanically fastened rather than glued traditionally.
@@Nomadboatbuilding What it would be for me is all hardwood. I have access to a saw mill so I have an endless supply of rough cut lumber specifically. Oak and pine are the easiest woods for me to get.
Then following the traditional rules of thumb is your best bet. If using oak, carefully consider the type of adhesive you use or be sure to back up with mechanical fastenings. For instance, oak doesn’t glue well with standard epoxy without taking extra care.
This video was all shot on a phone so some of the footage may be mirrored depending on which camera lens was being used. Like the bench vice for instance. That’s actually on the left side of my bench. Funny, I never even noticed that when editing.
