Joining boards

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Phil_S
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Re: Joining boards

Post by Phil_S »

Hey CBass! Thanks for the comments. Slow going here. Been stuck with no progress. Rain 5 days in a row and no sign of letting up means I can't get outside to make sawdust. I was pretty happy with the glue-up. I'm using a jig that seems to work well on the saw and I managed to find a good quality 40T blade for a reasonable cost. I'm using a Freud LU86R010 thin kerf all purpose carbide tipped blade. Some of the blades are just too spendy for me. I had to learn the hard way how to push the cherry through at the right speed to avoid burns. Cherry seems to burn easily.

I have an old Craftsman router that is a POS, but I think it will not be hard to convert it to one of these: https://www.youtube.com/watch?v=3f_8NF74DyI and then I think I'll actually have a real jointer for almost nothing.

I've been watching CL, but so far no luck!

I've got 4 boards and am ready to make the box. I came to realize, I've got a new (used) PC half-blind dovetail jig. I have to make 4 4-square pine boards to do some testing to make sure I understand about how to set the depth of cut. I've got another amp that needs a head case, too, so I'm hoping when I've got 4 4-square boards cut for the other one, that I can make a pine box for the other amp.

After that I will have to resaw some of the cherry to make thin panels for front and back. This involves yet another jig for the table saw. I'm hoping I can get all this done before it gets too cold to work outside. I have until about the middle of November.

Other tools I'm now wishing for are a planer and a band saw. Sheeks! There is no end of stuff you "need." I don't have room to keep all that stuff, so I've ruled out the planer (too heavy, too large.) I'm going to build an improved router sled for planing and maybe another large size bottom cutter. A used small band saw might still be on the horizon.
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JazzGuitarGimp
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Re: Joining boards

Post by JazzGuitarGimp »

Phil,

Before you jump into dovetails, and if you haven't already seen this video, you might want to go this route instead - it looks super simple. I am about to start a kitchen cabinet build, and was planning on buying a dovetail jig and router to make the drawer boxes, but I might just reconsider:

https://www.youtube.com/watch?v=NutwD7B6tmE

Cheers,
Lou
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cbass
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Re: Joining boards

Post by cbass »

That's a decent blade. A full width blade will give better stability through the cut but then you need a saw with the power to run it. Of you don't have a zero clearance insert get or make one.
I enjoy working with cherry other than the boogers . try some hard maple of you want to see some serious smoke. Chery is much softer than oak or pecan or hm.You've got some pretty squirly grain on that board. It'll be a tough one to work with a hand plane.
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cbass
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Re: Joining boards

Post by cbass »

Also you shouldn't be burning cherry ripping it with a new blade. Unless you have a real fine tooth blade and are really pushing hard on it. Make sure your fence is extremely parallel to the blade its better to toe out just a hair
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Phil_S
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Re: Joining boards

Post by Phil_S »

Minor burning due to inexperience. I believe I was loafing instead of feeding the board. I think I allowed it to rest momentarily, and more than once. It is just learning curve. That blade is a good blade, new and good 'n' sharp. No more burning now that I understand how that works.

After reading too much about table saws and blades on the internet and watching countless youtoobs, I concluded a full width blade is possible but not the best idea for my saw.

Lou, that's a real simple way to cut a box joint and I like it a lot. I had to make a decision when I bought the saw and there were lots of trade offs that played against a budget. I decided to buy the saw that consistently gets very high marks from reviewers and that has virtually no negative reviews. (There are always a few cranky people who should be ignored.) One thing I gave up was an arbor long enough to take a dado set. So, for me to cut box joints, it will be time consuming as I can only take a little less than 1/8" in each pass. I'd need to build some sort of sliding jig... or do it with the router ;-}

Edit: anything you need, youtoob: https://www.youtube.com/watch?v=WsgcB8QkkeQ execution is not elegant, but the idea is solid.
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JazzGuitarGimp
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Re: Joining boards

Post by JazzGuitarGimp »

Phil, when you put your sled together, how many boards (and their thickness) did you use to make the front and back rails? And how did you laminate them? I'm a bit concerned about the absolutely flat reference surface and the shear number of clamps (which I don't have) used.
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Phil_S
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Re: Joining boards

Post by Phil_S »

Lou,
I used odds 'n' ends I had around the house that my wife insisted many times I had to take to the dump. I'd encourage you to use what you can find if it fills the bill.

The front and rear fences are made from particle board shelf material that was laminated with wood-look plastic. IIRC, these came out of a bookcase that was discarded, as they were 30" each. This made it very flat and checking with a straight edge, I found it to be very true. I cut 2 pieces for each (1.5" thickness total,) sandpapered the faces to be joined and glued them together. They I had to square them up again with the saw because of extremely minor slippage in alignment. I think I used 4 clamps and it was enough. You can make clamps. Search youtube. Probably the cheapest are the ones made from plastic pipe. Just cut off some short lengths and slice out a bit. Use a bit of brute force to open them and snap them onto your work piece.

You can buy a "ready panel" 2'x4' sheet of MDF, particle board, or plywood* for around $5.

For the runners, I used a piece of maple I had bought for something else and never used. I was so very lucky that the .75" side of the stock was an unbelievable perfect fit in the slot, so I just ripped off a couple of pieces. Remember, you want them shallow enough that they don't touch the bottom of the slot.

I ran the sled back and forth a few times and it rubbed off a bit of black stuff from the slots. A little sanding fixed that. Then a coat of paste wax on the runners and bottom did wonders to reduce friction.

*The biggest problem I've got with the sled is balance. After making the cut, the sled is a fair distance from the front of the table and past the back edge of the table. The weight of the rear fence requires me to keep a hand on the sled to keep it from tipping, which is a bad thing to happen. I want to say the lightest material of plywood, mdf, and particle board is plywood. I will probably replace the front fence as soon as I can because of the balance issue.

You might use an ordinary 2x4 for the rear fence as long as the bottom is true, as you don't want it to apply any pressure to the plywood floor that might warp it. If you use regular lumber, seal the ends to keep it from absorbing the enemy, water. Nothing rides on the fence. AFAIK, its only purpose is the keep the two sides of the plywood floor together after you slice in the kerf.

Both fences are considered sacrificial parts. There is no glue on the bottom, only screws secure them to the plywood floor.

Phil
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Re: Joining boards

Post by JazzGuitarGimp »

Thanks, Phil. I have two 3" face clamps, four 24" ratcheting bar clamps, a handful of C clamps, and a shitload of cinder blocks :-)

I've been wondering about what might be the optimal depth (front to back) for a sled. Last night, I arrived at 36"; knock off and inch and a half for each fence, plus a half inch for slop, and I am left with with 32.5" of usable cut area. I hadn't thought about falling off the table once the cut is made, but I have three roller stands, so I'll just set one up at the back of the saw to support the sled at the end of the cut.

I actually plan on makeing two sleds, and dedicate one to box joints. I don't see a need for that one to be any more than 12" front to back, but it might wind up being wider, so that I can accommodate 15" wide boards (bass guitar and hifi cabinets) :-)
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Phil_S
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Re: Joining boards

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Mine is done on 24" sq plywood and I was surprised at just how right-sized it turned out. Initially, I was thinking I'd make it much less front to back, maybe 18", but that would have been a disaster, way too small. I did not fully understand (difference between thinking and doing) that front to back usable space is limited by the placement of the blade (d'oh!) and that the first 8-10" inches is useless space you need to have.

Right to left will depend on the size of your table. 36" would be awkwardly wide on my portable job site table saw and 36" front to back would probably be too difficult to manage. If you have an outfeed table, you will need to cut slots for the runners, but it will allow accommodation of a larger sled.

Mostly, I think I'd be concerned about being able to manage the sled comfortably. 36 x 36 strikes me as too large. Remember this is for cross cutting a board. Mine will take a board about 12" wide. Are you really going larger than that? If you do, then you can make a temporary jig for it, maybe one without much of a front fence. As for width, that mostly depends on what you intend to build. For a guitar amp head cab, about 20" is fine in my sled and I think 24" would be OK, too. It is OK to have it hang off the edge. I'm doubtful you need 36" for that. If you are building bed frames, then you'll need to figure out how to hold a ~7' rail for cross cutting and that's a whole different idea, for which you can find a solution on, you guessed it, youtoob.

Part of my issue in sizing the sled is the limit of my physical size. I am just under 5'6" and my sleeve size is 32", so big items quickly get beyond my comfort zone. It's not just size, it's weight too, as my short stature limits my leverage. If you are a larger person, and you have a bigger table (mine is about 22" x 24") then maybe 24" or 30" x 36" is fine for you. I don't think I'd go to 36" x 36". I don't believe bigger is better for this. In the end, you'll have to be the judge.
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Re: Joining boards

Post by JazzGuitarGimp »

I have an old Craftsman table saw. In fact, it's so old it's belt drive. But it's in good condition. I measured it today, and I've done a layout drawing for the box joint sled and jig. The cast iron portion of the table is 20" wide x 27" deep, and it has a 10" wide, stamped steel extension wing on each side, making the overall dimensions 40" x 27". I do not have an outfeed table. It looks like, in order to do a 15" long box joint, I will need a bit more than 15" on either side of the pin, plus I've included a generous 2" at each end for clamping the jig to the sled's fence. I plan on making the fences 1.5" thick, and the jig 1" thick. The attached pdf is what I came up with: The sled is 39.5" wide by 16" deep, and the jig is 35.5" long. The center of the saw's arbor is 9" from the back edge of the table, and with a 16" sled, I'll wind up with more of the sled on the table than sled hanging off the table at the end of the cut (16 - 9 - 2.5 = 4.5" hanging off).

EDIT: I will likely build another box joint jig for 3/4" box joints - I think 3/8" would work well for anything under about 8", but getting out toward 15", 3/8" boxes seems a bit tedious.

I haven't done a layout for the crosscut sled yet, but I expect it will be less wide but more deep.
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Phil_S
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Re: Joining boards

Post by Phil_S »

I have no specific advice. In general, I'd make these sleds as small as possible. They get awkward very quickly, both size and weight become factors. Consider the typical board size you'll be cutting and build for that. If you are cutting a 15" wide board for box joints, I'd say you need ~10-12" each side of the pin and you'll have adequate support.

If you want to do a very wide board that is 100% supported, think in terms of flipping the board half way through. For a 15" board, you can divide it 1/3 - 2/3 at the pin. If you have 7.5"" on the already-cut 1/3 side, flip the board when you are half way through.
Geeze
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Re: Joining boards

Post by Geeze »

The center of the saw's arbor is 9" from the back edge of the table, and with a 16" sled, I'll wind up with more of the sled on the table than sled hanging off the table at the end of the cut (16 - 9 - 2.5 = 4.5" hanging off).

EDIT: I will likely build another box joint jig for 3/4" box joints - I think 3/8" would work well for anything under about 8", but getting out toward 15", 3/8" boxes seems a bit tedious.

I haven't done a layout for the crosscut sled yet, but I expect it will be less wide but more deep.[/quote]

On the finger joint jig - the third one I made - it has a back flat section 5" or so behind the rear fence. Really helps keep the 30" boards stable. I plan to attach a bit of 2x4" to the rear slot to keep bits from nailing me in the crotch as I cut.

Phil -

You'd asked earlier in the thread about stain. Not a big fan on figured wood as the planks have zones of hardness that resist the penetration so the end result looks blotchy. Guitar guys seal the wood and then apply the stain to the finish to 'colorize' it. To get the grain to pop I use 8-10 tea bags in a 1.5 cups of water to make a Chernobyl strength tea wash. brush it on 3 times - doesn't seem to do much but when you finish my oh my - nice. I used this on a recent poplar cab to balance out the green to the tan.

Russ
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Phil_S
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Re: Joining boards

Post by Phil_S »

Hi Russ. Interesting idea. Somehow, the cherry looks a bit bland to my eye, but was concerned about uneven finish. I'm glad you mentioned that because I don't have the experience to know. I am thinking, it needs just a little something and tea sounds like a great idea. Thanks.
Phil
Geeze
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Re: Joining boards

Post by Geeze »

Hi Phil,

Tea is amazing - here is a before and after pic on the poplar. I dry the 'coats' of tea with a blow dryer. Then I slurry sand 320 let dry and then 400. Oil until the wood 'spits' it back out. Let dry and then polish with 0000 steel wool. Oiled wood is easier to fix than lacquer / epoxy surface finishes.

On something earlier you noted about the wood grain running in different directions. This is why I abandoned routers for rounding edges and why I cut finger joints before I finish mill the stock. Tear out brings tears to my eyes.

Also for the small dings, tears and gaps I use clear devcon epoxy to fill and then finish as normal. Figured wood or contrasting wood joints all of the epoxy disappears.

Russ
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Phil_S
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Re: Joining boards

Post by Phil_S »

Regarding tearout, I built a new router sled. The old one had the router screwed down to a piece of particle board shelf material. It had no stops on it and was subject to going off the rails, creating unwanted circular impressions :oops: .

The new one is safer and easier to control. The new one has a long narrow guide box with a slot for the bit and the sled rides the rails limited by a stop on each side. This one requires going across the grain (unless the work piece is less than 11" long). This one leaves the planed board looking like a fresh mowed lawn (stripes) with some tearout. It is almost as if the sled is tilted so very slightly, but that just can't be right as it's made from MDF and the low spots repeat at every lateral pass.

Anyway, it is a big improvement. The recent work with pine, I was able to smooth it with a jack plane set for a very shallow cut and the rest will come out with sanding. And I love that "voop" sound of the plane taking a shaving!

Sorry, no pictures of this. Maybe another day.
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