Best way to join wood end grain to end grain

[Tri Hoang]

I have access to a bunch of 6ft long, 3.5"x5.5" poplar. I would like to use them for my new bench that's about 8ft long. Although these are really nice boards, most of them have checks at both ends. Thus, after cutting off these checks, they will be around 5ft long. The bench top will be 4" thick.

I very much appreciate any suggestion on what join would be best to join these boards end grain to end-grain and strong enough to withstand the clamping pressure of the tail vise (twin screw)?

[Prashun Patel]

I'd stagger the boards so that each butt joint is sistered to a solid 5' piece. That'll be stronger than any kind of dowel/dovetail/loose tenon/finger joint you might use. I'd still use one of these types just to get the butts tight, but the strength will come from the edge grain glue.

[James Ogle]

You really don't need to worry about glueing the end grain. You are going to make a giant wood sandwich. Just stagger the shorts and longs, try for 3' and 5' or there abouts. Tak a full length peice and spread glue on one side, then place a long section of your cut up section even at one end, then a shorter peice, spread glue on top of those and repeat but start with a short section then a long section. Clamp those five peices together and let dry. Rinse and repeat until you reach your desired width. The wood will fail on a three foot long glue joint before modern glue applied correctly will.

I would definitely try to keep an 8' peice for the front and the back if you can.

[Sandy Stanford]

I have access to a bunch of 6ft long, 3.5"x5.5" poplar. I would like to use them for my new bench that's about 8ft long. Although these are really nice boards, most of them have checks at both ends. Thus, after cutting off these checks, they will be around 5ft long. The bench top will be 4" thick.

I very much appreciate any suggestion on what join would be best to join these boards end grain to end-grain and strong enough to withstand the clamping pressure of the tail vise (twin screw)?

Dovetail them by cutting two sets of tails....works like a charm.

[Sandy Stanford]

I have access to a bunch of 6ft long, 3.5"x5.5" poplar. I would like to use them for my new bench that's about 8ft long. Although these are really nice boards, most of them have checks at both ends. Thus, after cutting off these checks, they will be around 5ft long. The bench top will be 4" thick.

I very much appreciate any suggestion on what join would be best to join these boards end grain to end-grain and strong enough to withstand the clamping pressure of the tail vise (twin screw)?

This gives the idea, but they can also be cut by hand:

http://www.trend-uk.com/en/US/en/US/trend/content/content_detail.php?record_type=Knowledge&id=156

[Harry Goodwin]

For the face of the bench you might weant to add one piece of oak on the outside of the sandwich to make an indestructible bench. Oak would be a lot tougher than the poplar but would only need one board. Harry

[Kevin Groenke]

I have access to a bunch of 6ft long, 3.5"x5.5" poplar. I would like to use them for my new bench that's about 8ft long. Although these are really nice boards, most of them have checks at both ends. Thus, after cutting off these checks, they will be around 5ft long. The bench top will be 4" thick.

I very much appreciate any suggestion on what join would be best to join these boards end grain to end-grain and strong enough to withstand the clamping pressure of the tail vise (twin screw)?


I would do nothing or scarf the parts together.

A simple scarf joint will increase the surface area and provide a better surface gluing, it would probably be sufficient for this application. The problem is that a scarf for a 4" member is going to be 1/2 the length of the bench.

http://woodzone.com/Merchant2/images/glossary/scarfpict.jpg

I've seen many butcher block tops comprised entirely of butt joined shorts. I think that as long you stagger the joints, the strength of the glue on the face edges is sufficient to hold everything together. Use TB3 or some other superior glue.

Of course if you could finger join it would be stronger, but you'd need a BIG shaper cutter. You could throw some dowels or loose tenons in the end grain to keep things aligned, but square-cut end grain really cannot be adhered effectively(try gluing a bundle of straws together end to end). If you're really worried about it coming apart, a mechanical fastener may be in order. There are a bunch of options: from plain old I-bolts to Tite-Joint, Flip-Bolt, Zipbolt, etc...

http://wwhardware.com/media/products/s/sc298.jpg
http://www.constantines.com/ProductImages/hardware/fasteners/58L11.jpghttp://www.bizier.com/E/assets/images/Fasteners2.jpg
http://www.mcfeelys.com/img/fastcap-flip-bolt-FSC-0020.jpg
http://www.mcfeelys.com/img/zipbolt-product-photo-FSC-2600.jpg

[James Taglienti]

I would put a few biscuits in each joint just to be safe. If you want to keep it neander, maybe a small loose tenon or something, or even some dowels.

[Tri Hoang]

My gut feeling is that glue alone would be sufficient to join these boards on their faces. I want to avoid meta fastener in the top if possible. I am also concern about the possibility of the joint get pulled apart on the top side when the metal fastener is applied to its belly. Dowel/tenon/biscuit would help with alignment but are not more effective than just glue alone, I think.

I like the idea of a single, big dovetail on the face size of the boards. The boards will then be flipped on its edge to be on top. That way, only a small portion of the dovetail need to be flush (read...easier to hide my sloppiness)

It's big and bulky but I think I can handle it. The challenge for me would be to shoot 3.5" of end grain. My widest plane is #7 at 2-3/8". Any suggestion?

[Don C Peterson]

I built my bench from salvaged Red Oak none of the pieces was longer than about 3 ft. I staggered the joints making sure that each butt joint had at least 6" of overlap on the sides. I also cut grooves and used splines (think overgrown shop-made biscuits) to help keep things in alignment. Five years later, the bench is still ugly, but strong and stable.


For shooting the ends, I used a hand saw to cut close to final dimensions, but then used a router with a long spiral cut bit to trim flat and square. Just clamp a straight edge to the bench top to use as a guide. My top is not quite 3" thick so the spiral cut bit couldn't quite get all of it so I cleaned up the bottom with flush cut saw and a low angle block plane.

[Jim Koepke]

There are some good answers here. That may be because the question was clear about what you have and what you are trying to accomplish.

My thoughts are along the line of half lap joints. This would also help with the end squaring since only half the width would would have to be done on the shooting board. The half laps could include other fancy schemes like draw bore dowelling or fully hidden dovetail and socket to increase the tensile strength. That may ease the worry about your tail vice pushing them apart.

If possible, it might be worth the price for the piece in line with the tail vice to be a single piece. If it is a spliced piece, you may want to consider having the short piece closest to the vice. That gives the remaining length a lot of side support to assist in keeping it from blowing out. Maybe some dowels imbedded along this section will offer not only peace of mind, but added strength.

Another thought, the joining of all these pieces needs to be staggered to avoid a weak line across the face. Planned randomness may be stronger than equalized staggering. It is also likely one can make an appealing pattern and still have strength.

We want pictures of every single step...:D

jim

[harry strasil]

why worry about vise pressure pushing it apart, if you use good glue the wood itself is the weak link, just make sure and mark the splits you cut off as the wood may split more if its on the same plane as the glue joints. natural imperfection.

[Pam Niedermayer]

I'd say that scarf, half lap, or single big dovetail would do the job for you. I wouldn't rely purely on glue because, IME, while the glue is stronger than wood, the wood always tends to break very near the glue line.

Note that single big dovetails are relatively fragile in softwood; but the ones that fail will do so right away.

Pam

[Bob Smalser]

End grain isn't a gluing surface under any circumstances, the last thing you want in your top is hardware, and if you go to the trouble of cutting lap joints, why not cut the real thing instead?

http://pic20.picturetrail.com/VOL12/1104763/2595357/70507451.jpg

[Barry Vabeach]

Tri, I built my bench probably 20 years ago from wood that was 2 1/2 square by 36 inches at most ( some were 24) . I just glued them up James suggests. You will have a ton of long grain gluing surfaces from the adjoining plies, you won't need any metal. If you don't have a jointer or planer ( I didn't ) you only need to get each plie the same width, adjacent plies can be slightly wider or narrower and no one will ever see that. I also agree you will want something stronger than poplar at least for the side you expect to work from - I would suggest hard maple if you can afford it. Oak is a definite step up from poplar, but the top edge near the front takes a lot of abuse so that is where I would spend the money.

[Kent A Bathurst]

..... half lap joints.... include other fancy schemes like draw bore dowelling...worth the price for the piece in line with the tail vice to be a single piece.......the joining of all these pieces needs to be staggered to avoid a weak line across the face......

Bingo

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[Tri Hoang]

First one just got its surface clean. A little light weight but I think it's better for a bench than the construction lumber I could find at the borgs here.