Gluing large pieces of wood

[Jacob s white]

I plan on making a workbench out of 4 by 4 beams from home depot and am wondering if for the top of the bench if wood glue will be enough to laminate the beams lengthwise or if I will have to do some type of reinforcement like breadboard ends on a table

[Mel Fulks]

Pressure treated ? No!

[Lee Schierer]

Glue alone should be strong enough. However, if you are planning on gluing up 4 x 4 treated lumber you will need to let the wood dry considerably to get a decent bond. Due to the size and weight, I would recommend only gluing up two to start, leveling the face as you clamp it up and then add one additional piece each time after that to your initial glue up.

[Stewart Lang]

Folks have made tabletops out of 3/4" lumber for centuries. That has like 1/5 of the edge glue surface of those 4x4s. You'll be just fine, don't worry :)

[Mel Fulks]

I don’t think they are gonna be flat enough for glue. If it must be done ,use the polyurethane cartridge adhesive. If it does stay together,
how will it be flattened ?

[Richard Coers]

IMHO, no one needs a 3 1/2" thick bench top. Construction grade 4x4s will be very wet in the center. Many of them will have the log center in them and when that is not centered, the 4x4 will twist like crazy. Expect a lot of cracking as those dry out. Just not a good idea in my opinion.

[Alan Schwabacher]

You could do it the way I did. I would sort through the douglas fir 4x4 stack, choosing a few of the straightest ones with the tightest grain to let dry in my shop.

When I had accumulated most of what I needed, I happened on a closing shop selling maple at half the price of the fir. My maple bench has worked out well.

So yes, buying 4x4 lumber for a bench can work out.

[Ron Citerone]

IMHO, no one needs a 3 1/2" thick bench top. Construction grade 4x4s will be very wet in the center. Many of them will have the log center in them and when that is not centered, the 4x4 will twist like crazy. Expect a lot of cracking as those dry out. Just not a good idea in my opinion.

I agree with Rich here. I would consider all options before commiting to this idea. As far as the glue stength you would be fine I believe.

[Andrew Seemann]

As mentioned above, boards with pith in them (the center of the tree) are very problematic, and many 4x4s contain pith. If you are lucky some Doug Fir ones might not. 4x4s with pith typically will crack along at least one side sometimes more. It is just a geometry thing with how concentric rings dry.

If you are determined to do a construction lumber top, you probably are better off taking untreated 2x6s with no pith and ripping them down the middle and then gluing up the 2x3 sections on their sides. That way you end up with a roughly quartered or rift sawn top, which will be much more stable.

[Alex Zeller]

If you really want to do this I would just drill 1/2" holes in them and get some threaded rods and bolt them together.

[Dan Hahr]

4x4 pressure treated posts will make a disaster of a top. Rip some 2x12s down to whatever you can get and let them dry and settle. Then plane then down and glue them up in batches. Flatten each batch carefully and glue those together. That is your best bet if you're using construction grade lumber.

Dan

[johnny means]

Hmmm, my local HD has sold 4x4 fir fir as long as I can remember. Maybe this discussion isn't about pressure treated. Edge gluing will be plenty strong for a workbench top, it's been done that way for centuries. Of course, you'll need to be sure that your material is properly dry, and prepared and that you have adequately clamping. And yeah, no PT.

[Ryan Yeaglin]

IMHO, no one needs a 3 1/2" thick bench top. Construction grade 4x4s will be very wet in the center. Many of them will have the log center in them and when that is not centered, the 4x4 will twist like crazy. Expect a lot of cracking as those dry out. Just not a good idea in my opinion.

Correct, many of today's 4"x4"s are junk and contain the pith from the log which will warp and twist. PT lumber has many detractors to me for building a work bench, namely it's soft wood and doesn't have the mass for a workbench like oak or hard maple.

[Richard Coers]

Hmmm, my local HD has sold 4x4 fir fir as long as I can remember. Maybe this discussion isn't about pressure treated. Edge gluing will be plenty strong for a workbench top, it's been done that way for centuries. Of course, you'll need to be sure that your material is properly dry, and prepared and that you have adequately clamping. And yeah, no PT.
I was talking construction grade, not PT. My local Menards shows 4x4 in; white wood, douglas fir, western red cedar, redwood, and even oak.

[Jim Matthews]

I was talking construction grade, not PT. My local Menards shows 4x4 in; white wood, douglas fir, western red cedar, redwood, and even oak.
Do you own a moisture meter?

[roger wiegand]

I don't think he said anything about using PT wood. Why would he do that? We get quite nice KD fir 4x4's here that stay straight, mill nicely, and would make a fine top. Sometimes I buy them when I need straight 2x4's and rip them in half because the quality is so much better than the 2x lumber. Glue is more than sufficient to hold them together.

I don't know whether anyone "needs" a 3-1/2" thick top, but I enjoy the relative immovability of the beech top on mine that is that thick. Many old benches are that thick or more to provide mass.

[Tony Shea]

My benchtop is 4x4 doug fir from pieces I picked up at HD. I picked through the batches until I had enough clear straight pieces. I jointed and planed each piece to get a tight glue up with no issue. I did a standard edge glue up with no biscuits, dominos, etc. There is absolutely no issue with using regular glue.

I highly recommend using the best wood you can afford. I have had my bench top for about 6 years at this point and it has served me very well. But I do lust for a solid maple bench top that is at least 3" thick and will hopefully go through with it this year. I made my base using solid hard maple in the Roubo style with 4"x5" legs. The base will last my lifetime and will be a great place to put a sturdy maple top. The doug fir is just a tad softer than I want and gets dinged up a little too easily. I use hand tools about 75% of time so rely on my bench top more than some woodworkers. Therefore having a stable thick bench top is a top priority for me.

[Don Stephan]

Ripping 2x6's may be okay. For my first try at a bench top I ripped 2x8's, because I wanted yellow pine thinking it would be harder than SPF in 2x6's. Every ripped piece warped noticeably and required more jointing and planing than I had anticipated; some warped so much they were unuseable.

[Jerry Olexa]

I would recommend you NOT use 4X4 treated for your top from HD.....You would have challenge later in flattening and PT tends to be warpy or curly ....I believe you'd even be better with standard 2X4's laid on end and laminated..I'd avoid pressure treated for interior use..esp 4X4s.

[Gordon Stump]

Wood glue is more than enough for this application.