Simple jointing for thin boards

[John Coloccia]

This works for thicker boards also, but it really shines for thin boards (a problem acoustic guitar builders face every top and back). Maybe someone will find this useful. I've found that thin boards simply don't joint well on a power jointer, and using a plane is inconvenient because sturdy clamping is difficult. You COULD build a shooting board (like I have room for another jig in the shop), but honestly a lot of the woods I use, especially brittle woods, just sand so much easier than they plane. I usually just clamp them in my bench, and then clamp a couple of boards on either side, near the top, to keep it straight and make it sturdier, almost like a saw vice. Yank out my No.7 jointer, eyeball it and go. I get good results, but you have to be awake and it really needs to be done very precisely.

So this is what I've been doing lately.

I stick some quality 3M self stick sandpaper to my tablesaw top. Have I mentioned how much better 3M Fre-cut gold is compared to most sandpapers? Well it is. Anyhow, I stick it down, and move my table saw fence to overlap it slightly.

http://i913.photobucket.com/albums/ac335/jcoloccia/Simple%20Jointing/DSC02027.jpg


The fence acts as the fence on a jointer. It helps me keep everything square. The particular top I'm jointing here happens to be cedar. I do both sides at the same time. Use one hand to hold it against the fence, and the other to rub back and forth.
http://i913.photobucket.com/albums/ac335/jcoloccia/Simple%20Jointing/DSC02028.jpg

Rub back and for for about 10 seconds. I can't see the joint. Can you?
http://i913.photobucket.com/albums/ac335/jcoloccia/Simple%20Jointing/DSC02029.jpg

I hope someone else finds this useful.

[Prashun Patel]

That's a great idea. Thanks.

[Scott T Smith]

That's a great idea. Thanks.


+2 - very good idea!

[JohnT Fitzgerald]

excellent idea!

Coincidentally, this showed up in today's Woodsmith email 'tip of the day' to which I subscribe. It's good to know that it works well from real-world experience!!

[John Coloccia]

excellent idea!

Coincidentally, this showed up in today's Woodsmith email 'tip of the day' to which I subscribe. It's good to know that it works well from real-world experience!!

Wow. Now that IS a coincidence. I just started doing this about a month ago and I thought to post it because I used it on a bubinga back last night that was particularly brittle and uncooperative. Yes, it absolutely works.

Based on what you just said, I just went out and subscribed to Woodsmith's tips. Sounds like there's actually some useful stuff in there. I figured it would be things like "save your baby food jars to store screws and other small items".

[JohnT Fitzgerald]

lol @ baby food jars!!!

There are some decent tips in there. I like it because they usually arrive in my inbox mid-day, so it's a nice mental break from work :)

interestingly, the 'topic' for the tip was to keep sharp, crisp corners and edges when sanding. they didn't mention the 'brittle' wood aspect.

[Neil Brooks]

Thanks, John. A good one to know.

I was wondering, too, whether you couldn't use a _known_ straight edge (rather than just, say, a router guide), and a flush trim bit, and joint, that way.

Is that already a viable option, or ... did I just make it up ? ;)

[John Coloccia]

Thanks, John. A good one to know.

I was wondering, too, whether you couldn't use a _known_ straight edge (rather than just, say, a router guide), and a flush trim bit, and joint, that way.

Is that already a viable option, or ... did I just make it up ? ;)

Some folks do it like that but I never found that it gives me a precise enough joint. I guess it depends on your definition of a "good" joint. For instruments, it just doesn't seem to cut it...at least not when I've tried it.

I really switched to this to deal with uncooperative woods. Brittle, high figure, etc. It's just so easy to have a piece chip out on the power tools, and even with hand planes. For the cedar I did in the photos, I could almost as easily have done it with a hand planes but the sanding method is so easy and foolproof, a monkey could do it reliably. Heck, even *I* can do it reliably, and that's saying something. This woodworking stuff didn't just come to me. I had to really work at it, and anything that takes my skill out of the equation but still gives me results as good as I can do by hand, I'm all for :) I could never get a perfect joint on my jointer anyhow, even with thicker woods (say, 1"), and always had to follow it up with hand planing. Now I rough the thicker boards on the jointer, and finish up with a few seconds of sanding.

The difference between the "good" power tools joint and a near perfect joint is obvious when you see them side by side. I often have to be extremely careful to always keep a centerline on the work. If I accidentally sand it away entirely, I usually can't find it again without measuring unless the wood coloring or figure makes it obvious (like in the pictures, the joint is that dark line down the middle, but it's only visible because the bookmatched top makes it obvious and there just happened to be dark grain at the joint. If it were a "clear" top, it would be absolutely invisible, like it is at the bottom of the picture where the wood is clear).

Keep in mind that I have consumer power tools. Jets, Grizzlys, etc. I'm sure there's machines out there that can be tuned to near perfection and that give results as good as hand work. I just don't happen to own any :D

[Neil Brooks]

Excellent answer. Many thanks.

Along those same lines, I'm for anything that can take the guesswork out of woodworking, and allow me to get more precision/consistency with less effort.

So ... I hear ya' :)

[Mike OMelia]

When I am jointing a book matched set, I start with a "thicker" piece. I pass both together through the jointer, then finish sand as mentioned above by the OP. I use a spanish jig to pull the pieces together (ropes and wedges... VERY effective). After dry, I run through my drum sander. On my spruce tops, very difficult to find the actual seam. In fact, I mark the seam on the edge so I can do proper centering. I find that trying to joint 0.08 to 0.11 boards is unsafe (can fail) because it is difficult to apply enough jointing pressure due to the flexible nature of the work pieces. By starting with something that is 0.18 or so, makes all the difference in the world. And thickness sanding to the final desired thickness removes any imperfections.

Just my thoughts. Thanks for opening this thread!

Mike

[Aaron Hancock]

looks like it works great, but I was always taught not to sand and surface that will be glued..

[JohnT Fitzgerald]

I was always taught not to sand and surface that will be glued..

Can't say I've ever heard that one before....

[John Coloccia]

I've heard that and I've been ignoring it for many years :) You do have to be a little careful with sawdust filling up the pores, especially in porous wood. I always clean the joint with a stiff bristle brush, and then blow it out to get it as dust free as possible. If it's a particularly difficult wood to glue (cocobolo, for example) I'll clean it with alcohol first to remove all the sawdust and oils (I use the same as I french polish with....Graves XXX. Everclear's good too).

Whether any of that matters or not, I don't know, but it's my ritual and my joints don't fall apart, so I don't plan on changing now :D

[Alan Schaffter]

Whatever happened to jointing on a router table?

You need a router table with a split fence where the outfeed half is adjustable separately (original NYW router table, INCRA LS, etc.) or just double stick a thin strip to the outfeed fence and adjust it to the bit instead of the infeed fence. It works well with very thin stock.

I have also heard of guys clamping a couple of thin pieces between two thicker boards and just using the jointer.

That is the beauty of woodworking- many ways to skin the cat!

[Matt Day]

That's a great idea! I use the same technique on veneer.

[Dave MacArthur]

Interesting and good idea.

NOW I really want to read about some of your guitar work, John! I'll have to search for any project threads you may have posted, or hope you do post some pics of your tops/back etc.
Thanks!

[John McClanahan]

Great idea!

interesting, my Woodsmith tip yesterday was "How Yo Prevent Tearout On The Miter Saw."

BTW, I'm not a fan of glass jars for hardware. Sorting small screws from broken glass on the floor is a pain.

Now, back to the original topic.

John

[John Coloccia]

Interesting and good idea.

NOW I really want to read about some of your guitar work, John! I'll have to search for any project threads you may have posted, or hope you do post some pics of your tops/back etc.
Thanks!

Here's a photo of the bubinga back I did a couple of nights ago...in fact, the one that made me think to start this thread. The back stripe is cocobolo with white-black-white thin lines made of maple and mahogany veneers. I'll tell you a little secret: this particular back is held together with superglue. There's all sorts of dos and don'ts in woodworking/instrument building, and I seem to just break them all.

http://i913.photobucket.com/albums/ac335/jcoloccia/Simple%20Jointing/DSC02030.jpg

[Dave MacArthur]

Looks nice!