Advice for building a long span workbench

[seaphoto]

Hello Everyone,

I would like to replace a wall mounted bench in my shop that is built on particle board cabinets with something that has an opening underneath to put a model ship, which needs about 9 feet of clearance to safely store (yep, it's a big one!) . My question is the long unsupported front of the bench, which will be built using 2 X 4 X 10 Douglas fir. Using one stick, I am sure it will hog in the center, so I was thinking about laminating two or more, perhaps reinforcing with plywood or steel held in the middle with carriage bolts. I am very open to suggestions though, especially if you have experience with this this type of span. The bench top will be 24" deep and used mostly to store tools as I have other mobile benches for my work that are nice and strong.

Thank you very much for any help or guidance.

Kurt

 

[dadsEH]

Hello Everyone,

I would like to replace a wall mounted bench in my shop that is built on particle board cabinets with something that has an opening underneath to put a model ship, which needs about 9 feet of clearance to safely store (yep, it's a big one!) . My question is the long unsupported front of the bench, which will be built using 2 X 4 X 10 Douglas fir. Using one stick, I am sure it will hog in the center, so I was thinking about laminating two or more, perhaps reinforcing with plywood or steel held in the middle with carriage bolts. I am very open to suggestions though, especially if you have experience with this this type of span. The bench top will be 24" deep and used mostly to store tools as I have other mobile benches for my work that are nice and strong.

Thank you very much for any help or guidance.

Kurt

So whats wrong with installing a removable centre support leg after you park the boat?

 

[fitz11]

I have a 10' shelf in my garage built similar to a bench. I used 2x4's doubled up in front and back and plywood on top. It's stable but sags a bit. For a bench I would do 3 sets of 2x4's with plywood on top and you shouldn't have any problems.

 

[Ruthless53]

I built something like this for a shelf I needed really strong. Used half inch plywood and wood glue and built a frame between the brackets! Used timberlok 6 inch lag screws to attach to studs. On a 3 foot shelf with only 2 braces I had 130lb airconditioner plus me (260 lbs) for about 3 min. It's really strong!!

 

[Ruthless53]

Here's a pic I edited where you can kind of see what I did. You would put supports below for a bench.

 

[Kevin54]

When I built my bench, I framed things out as far as the top and had temporary legs to hold the top framework. Once I had everything leveled, I then started cutting some supports that go from the benchtop and angle back to the wall. I don't like things down to the floor where I can clean out underneath, or where I will get things wet if I choose to wash the garage out.

I don't have the pics on this computer, but when i get into the house, I'll pull up a few pics from my other computer.

 

[BikerDad]

Since your description is unclear as to how you're going to orient the support, I'll just toss this out. Use a single 2x6, oriented on edge. If you're really worried, use two. If you're super dooper worried, and you'd like to be able to host a hoe-down on the benchtop, just laminate a passel of 2x4s together to make the top, resulting in a top that is 10' long, 24" wide, and 3.5" thick. (Note that actually getting a flat top will reduce your thickness to about 3.125" to 3.25") One thing you should do is establish exactly how far apart the legs are going to be. Even with a 9 foot Iowa class BB docking in there, they don't necessarily have to be 9' apart. That BB can shake, shimmy and jive its way in to a space where the "entry" is as little as 7' probably, IF the ends aren't closed. Another possibility is simply loading, er, docking from the end, in which case bench leg spacing is untethered from the length of whatever is being stored.

Per The Sagulator, the laminated top above, made from Douglas Fir, with legs on the very ends, will sag less than a 1/4" TOTAL with a 500lb load on it. Move the legs in @2ft each and your top will be able to support over a ton, with less than 1/4" of sag.

http://www.woodbin.com/calcs/sagulator.htm#edge_strip

A simple 3/4" plywood shelf, with legs at the very ends, with the support of a 2x6 on edge, will be able to support a load of 25lbs per foot without sagging.

Have fun playing with the Sagulator.

 

[JakeKohl]

you might also consider putting the shelf on drawer slides to make loading and unloading that mother easier.

Build it like you would frame a floor...place a doubled up 2x6 front with a 1/2" plywood filler (like a header) shored up with legs on either end of the span. Then run run 2x4s (or 2x6's) from the wall out to your front/header. That is, assuming you have the height to spare for the 2x6 beam. You could also go with some steel tubing - a 2x4 square section should do the job nicely (or two 2x2 square tubes, which are REALLY common and inexpensive, stitch welded together every few inches).

 

[RivennHewn]

Google torsion box

 

[theoldwizard1]

Follow these plans on YouTube. Simple sturdy workbench build by Matthias Wandel

For a 10' span, I would use 2x8 for the front and back rail. Standard construction grade SPF (spruce/pine/fir) is fine. Lay some 2x4 flat across the bottom leg braces and screw them in. Space them to fit your cradle.

you might also consider putting the shelf on drawer slides to make loading and unloading that mother easier.

Good idea ! Screw the draw slides perpendicular to the 2x4. You may be able to screw you cradle directly to the slides. If not, just use 1/2" plwood dor a deck.

 

[Myerfire]

The torsion box.


Sent from my iPhone using Tapatalk

 

[rick carpenter]

I'd say go with a torsion box or use BikerDad's suggestion for the laminated top with one modification: try using a 2x6 or a 2x8 in place of one of the middle 2x4s. Then you could run supports angled back to the wall where you want the underneath open.

 

[woodrail]

2 pieces of unistrut form Lowes or HD with the top bolted to it. Easy peasy

 

[AZ Pete]

You should really build a torsion box for the top.

 

[seaphoto]

Thanks for all the suggestions! The reason I want the space open is that it will function as a display area in addition to storage. I will probably put a sheet of thin plexi in front as a dust shield.

@Woodrail, I have never used Unitstrut - looked it up and it looks promising. The next time I am down at Home Depot I will give it a look and see how rigid it is. Thanks everyone for the great help!

 

[Doozzee]

Buy a header or take 2x8s and plywood and make your own! Should work orjust run a steel beam

 

[JakeKohl]

torsion top will work too. I built one on my mobile workbench.

 

[seaphoto]

From what little I have seen about torsion tops, don't the top and bottom skins have to be one piece? If so, and I go over 8 feet, I am not sure how I would handle that.

Thanks

 

[teal95]

They make plywood bigger than 8'. I have dealt with 4'x14' before.

 

[theoldwizard1]

Okay you experts ! Why is a torsion box a good choice FOR THIS APPLICATION ?

Most of the examples I have seen are for bench tops that are nearly square, not your traditional rectangular workbench.

2x8 rails and flat 2x4 stretchers are way more than adequate. Rip 2 sheets of 3/4" plywood to your desired bench width. Make opposing 45° cross cuts to the desired length and glue the sheets together, securing them to the rails with cleats from underneath like in the video I referenced before.

You are basically building a floor supported on 2 ends. The 2x8 rails are the joists Check your joist span table. 2x8 are plenty.

Some people are just into OVERKILL !!!

 

[AZ Pete]

Old wizard. The bottom sheet is under tension, which makes the unit very stiff. This will provide a stiffer top with less thickness. I agree that torsion boxes are often built to be assembly tables, that doesn't mean that they are not good for long span bench tops.

 

[JakeKohl]

Okay you experts ! Why is a torsion box a good choice FOR THIS APPLICATION ?

Most of the examples I have seen are for bench tops that are nearly square, not your traditional rectangular workbench.

2x8 rails and flat 2x4 stretchers are way more than adequate. Rip 2 sheets of 3/4" plywood to your desired bench width. Make opposing 45° cross cuts to the desired length and glue the sheets together, securing them to the rails with cleats from underneath like in the video I referenced before.

You are basically building a floor supported on 2 ends. The 2x8 rails are the joists Check your joist span table. 2x8 are plenty.

Some people are just into OVERKILL !!!

Oh, it would definitely be overkill! It's what we do.

 

[seaphoto]

Thanks for all the advice! I went ahead and built it like a floor joist system, but reinforced the corners with 11/16" dowels like the video showed, just for that overkill factor. It's plenty strong, and I am confident it will resist sagging.

Not only did I build it like a floor, but I was at the local Habitat for Humanity store today and found some boxes of nice pergo style flooring I will use for the top. Years ago I did this with a bench and was very pleased with the durability of the top, and of course, it looks great. For 13 bucks, I got enough for both the top and bottom shelf, so the Gneiseanu will be stored in style!

Anyways, thanks again!

 

[theoldwizard1]

Thanks for all the advice! I went ahead and built it like a floor joist system, but reinforced the corners with 11/16" dowels like the video showed, just for that overkill factor.

Doweling the corners is not "overkill". Screwing into end grain will always fail, which is why dowels or pocket screws work so well in those applications.

How big did you make the rails ? 2x6 or 2x8 ?

 

[Justanoldguy]

Use an L shaped bracket bolted to the wall.
Make it out of angle iron.
Put that in the centre of the bench.
Use two if you want more load on the bench.

 

[vankaye]

Under the work bench is such valuable space... Why not mount it up on a sturdy shelf where it can really be seen??

 

[seaphoto]

I used a 2 X 6, as I made it shorter than I originally planned. Since the ends were open I followed Bikerdad's advice about sliding her in. The back rail is lag bolted to the wall so that will help a lot with the strength as well.

I didn't want to store her anyplace where I had to lift above my head - she is heavy, even without the batteries, and as I progress on the detail more delicate - not the best combination, I'll stipulate, but that is the hobby I enjoy. For me it made more sense to remove a bank of cabinets that were junk collectors and use that space for the battleship.

I move her by removing the superstructure and grabbing two frames that are bonded to the inside. This is how I put her in the water, and so moving her under the bench works the same way. I have two rolling workbenches that I use as my main work surfaces, so I will roll one up to the wall mounted bench, pick her up and tranfer, and then it's off to detail town.

BTW, the rolling benches are based on a design I saw on the New Yankee Workshop:

http://www.newwookiee.com/story/New_Yankees_at_Work_Work_Table_Clamp_Cart_129796.asp

I used a sheet of plywood for the top instead of building the torsion box (sorry guys) and topped it with some counter laminate from Lowes. When I built the first it was so stable and handy that I replaced my second stationary table with another. When off the rollers, they are the same height as my table saw, so I can use them for infeed and outfeed when needed.