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Working from plans...I did my first scarf joint with a plane. I felt it was a pain to do. Plus not good results. Maybe after 2 yaks it is dull? Anyhow....Wouldn't it be better to use a sander. I will be borrowing a belt sander as opposed to using my ROS. Kim
20 replies:
RE: Scarf joints
Here's a picture that fits....sorry
RE: Scarf joints
Hi Kim, I used a belt sander on mine with good results. Sanding does close up the wood pores which supposably causes a weaker joint but a poor fitting joint causes bigger problems. A router or plane opens the pores up and lets he glue soak in better but either method works just fine. Chris
RE: Scarf joints
ChrisJ On the jig,..Is there a web page with more detail. The angle of the slot in the side wall? I do have a router but really haven't used it. Got it as a gift many years ago. Chris Thx for the tip. Undetermined which route I will go at this time. Kim
RE: Scarf joints
It was my own design so I don't have too many other details to add. The side slots are cut at an 8:1 rise. The slots were cut with a router with the side panels stacked so that they are precisely the same. The bed on this jig was 11" as I made it for my CH16's but it was easy to modify for scarfing the extra wide bottom panel on my MC16.5. You've really got to get that router out of the box. It's a very versatile tool for getting precision results especially when using it as a cutting tool. You can see a larger image of the jig at: http://www.flickr.com/photos/algonquinpaddler/278624487/sizes/l/in/set-72157594510381189/
RE: Scarf joints
Kim, I wouldn't be surprised if your problem with scarfing was indeed caused by a dull plane iron, as you suggested. A sharp plane is a joy to use on any task, including scarfing, but using a dull plane is about as much fun as shaving with a dull razor. (IMHO) I recommend getting a sharpening jig (I use a Veritas, it's great!), and learning to use it. I think you will find the investment of your time well worth it.
RE: Scarf joints
Yeah, sharpen your plane blade regularly. A sharpened blade will cut better than a new one, and if you stay on top of it, it won't take long to touch it up again.
RE: Scarf joints
I ordered the Veritas Sharpener. I may try the jig. My figures say a 7 degree angle. I am in luck with my hull panels. My lumber was over 8 ft. I will cut out the old scarf and do a new. Kim
RE: Scarf joints
Ahhhhhhhhhhhh, my sources tell me an 8:1 rise is an 8 degree angle. I was close. Been 35 yrs since I used math. What is the best way to measure this? Kim
RE: Scarf joints
Been a long time since I had to think. I overlooked your last post Chrisj. I found the formula. I will use an inch rise per 12" run. Kim
Thanks
RE: Scarf joints
I've learned a lot about sharpening planes by making mistakes, discovering some basic misconceptions I had, and by experimenting a lot. If you have any questions I'd be happy to share what I've learned. Since starting on my CLC boat, I've learned how to keep my Stanley block plane from good ol' CLC sharp enough to shave with, so I've figured out "my way". True, there are probably much better ways of doing things, as I'm not a woodworker; I'm a slow worker; and am still learning. But the beauty of this forum is that not-so-great advice from one person often attracts better advice from others.
RE: Scarf joints
To calculate the angle for a known rise and run you can either use the tan-1 function on a calculator, or In Google We Trust. Type into the main Google search box and ask it to calculate the arctangent in degrees like this "arctangent (1/8) in degrees" and it returns 7.12501635 degrees 1" in 12" is 4.76364169 degrees Be careful not to use radians if you want degrees, with either a calculator or Google.
RE: Scarf joints
For sharpening plane blades, do a Google search on "scary sharp" plane blade sharpening. It's done the rounds of the woodwork forums over the years. Basically involves glueing different (progressivly finer) grades of wet & dry sandpaper to flat glass, and running the iron over these (in a sharpening jig if required). Rougher grades take off the nicks, finer ones sharpen until you get to 2000 or 2500 grit (finer frits are available from automotive painting stores too). I get a mirror-finish on my blades and can do a coupe of full scarphing session without touching it up (the test is to try shaving with it). Sharpening stones obviously work too, but a lot of woodworkers now swear by the sandpaper method. Hope this helps if you stick with planing. Regards,
Darren
Melbourne, Australia
RE: Scarf joints
Degrees is what I know. What then is the rise per run? Kim
RE: Scarf joints
I kind of use the scary sharp method, but have made some significant modifications over the years. If you use scary sharp, I hope you will try these tips and find that they make the job faster, cheaper, less messy, and more fun. If the iron is very dull, I use a file at the beginning, not sandpaper. The Veritas jig works just fine on a file. You will would go through several dollars worth of 60 grit paper and spend a lot of time otherwise. If you can find good 30 grit paper, that works about as well as a file, if I recall. I start with good 60 grit paper, or plain aluminum oxide if I don't have the good stuff. I used to glue the sandpaper to the surface, as scary sharp method says. It is very messy, very time-consuming, the adhesive is expensive and gets all over, and it is of no benefit. Simply hold the paper down with one hand and push the iron (in the Veritas jig) with the other. Never wet the paper. It's a mess and doesn't do much, near as I can tell. On ordinary, cheaper, aluminum oxide paper, the paper will be dull after four strokes. You'll feel the sudden loss of resistance and the change in the sound. With the Norton bluish-colored stuff, it will still have some bite at around 16 strokes, so it's worth paying a little more for it. From 60 grit, jump to 150 or so. You don't need to use every gradation as you would if sanding wood. From 150 jump to a coarse waterstone (320 or 400 or whatever they are, I don't recall). If you stick with scary sharp and continue to use sandpaper after 150 or 220, you will use a great deal of expensive sandpaper. The waterstone cuts FASTER than paper and and costs nothing after the initial investment. Instead of throwing away another sheet of sandpaper every three minutes, you simply dunk the waterstone in the water and voila--it is as sharp as when it was brand new! After coarse waterstone, go to the coarse side of the CLC waterstone (1000 grit), then the fine side (6000 grit) if you are particular. I always do this, but to be candid, I suspect its just because its fun to have a really sharp plane.
RE: Scarf joints
Kim, Rise per run is the dimensionless ratio of the vertical side of a right triangle to the horizontal side, basically the tangent of an angle. It's a useful and exact way of expressing angles when you have a tape measure instead of a protractor and don't want to fool with arc-tangents. It's the standard in the construction industry. In m.c.'s example, since you go up 1 inch (rise) over an 8 inch length (run), the rise per run is 1/8, the tangent is .125 and the angle is 7.12501635 degrees. Laszlo
RE: Scarf joints
Laslo Whew. I went to a site that measured slope and got thrown off course. Their example happened to be for an 8 degree slope. Now to re cut my sides to the jig and do some scarfing. Thanks to all Kim
RE: Scarf joints
I have a blatant lack of woodworking skills and a matching collection of poorly maintained tools! so this little tip for sharpening a plane was a godsend to me: loosen the blade, drop it about an inch below the base and lock it there, place your stone on a flat surface (bench, offcut), place blade on front edge of stone and slide plane foward keeping blade level on the stone and heel of plane on the flat surface...repeat... start with coarse side of stone, finish with fine side when done return blade to its normal position and go make ribbons instead of dust! Kind of an instant jig. I always just eyeball the "inch" and I guess it must be all relative to the thickness of the stone, length of plane..., The experts will probably cringe but for me it beats the heck out of a blunt tool or complicated blade-removey-jiggy stuff. Any tips on how to use this set-up to get a 'correct' angle and make it repeatable would be cool! Dave P
RE: Scarf joints
Wow, what a great idea! I can't wait to try it out when I get back to the workshop (not for a couple weeks). By then, someone will probably have posted an answer to your request for a "correct" and repeatable procedure but if not I will to come up with something. The procedure doesn't need to be accurate (doesn't need to be exactly 25 degree bevel, 30 degree hone angle, for example), but it does need to be precise (ie repeatable.) Reason it this. If you sharpen a second time at a different angle, you might not get any sharpening of the edge, only a new beveled surface away from the workpiece that does nothing at all.
RE: Scarf joints
Jig box done. Measured both sides. I thought it was even. Not quite right. Not a very even scarf. I tried using my ros. Got a perfect scarf in practice with minimal difficulty. I may be biased but it is better than laser cut. Kim
RE: Scarf joints
» Submitted by Chris J. - Mon, September 1 » 10:33 AM
If you have a router, some scrap plywood and a couple of hours, you can rig up a scarf jig that takes all the guess work out of making scarf joints. Once complete, the scarf edges are feathered so fine that there's no need to leave any gaps when gluing them up.