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Hi,

I just finished building my bench 2'x5' and have couple questions.

-Do you guys remember what kind of finish you used? I'm especially interested for top since that's where my hand and guitar will be touching most of the time.

-How do or did you ensure that your top is flat? I'm guessing no bench or table will be perfecly flat but what is allowable and what is not? Wouldn't this matter in guitar building even if you are using a mold to join the sides?

Only tool that I have that tells me if things are level is bubble in my 12" combination square. I placed on all parts of my bench and altough the bubble goes to center in most parts, some of the parts make the bubble slighly left or right. I know this is probably not the most accurate tool to check the flatness, but I don't have anything else at this point.

Thanks for the help!

-David

I did, but it's not pretty or workmanshippy. Not a heirloom piece. Cheap, though; unfinished pine (1.5" x 3.5", roughly, from memory) legs, lapped cross members, bolted together with M10 bolts (I think...3/8", roughly), with a full sheet of 22mm MDF (3/4") ripped lengthwise and glued together, doubling the thickness, with a few pine cross beams across the width at strategic locations (have three sets of legs) stiffening, and a melamined chipboard worktop. Also a shelf just off the floor, resting on the bottom cross beams, and another higher up, resting on s'more heavy lapped and bolted cross member, and some pressed steel angle brackts for the middle bit where I didn't want to waste storage space. It's also bolted to the wall, because the shop's tiny, but even when it stood free it was pretty rock solid. With two full sheets of MDF, it's HEAVY. Only thing I would've added would be some length-wise members if I wasn't bolting.

Picture:



It's a bit of a mess, and is about 1/3 of the total surface area of my tiny shed shop, but it has a number of advantages: it's cheap, easy to clean, nothing much sticks to mealmine (glue-proof, pretty much), I can drill holes in it for fixtures with gay abandon, and if the top gets too beat up, I'll simply replace it with a fresh sheet of melamine at minimal cost. I'm going to be installing a router in it permanently at one end, have also made a small plug to plug the hole when it's not in use so I can still use the surface for other things. Only thing I need now are some longer (3/4" to 1" long) countersinkable 1/4-20 machine screws, which I can't find locally...

As for flatness, it's stayed pretty well put, and you want to check it with a straightedge. Which is an abosultely essential tool if you're building guitars. It doesn't really need to be perfectly flat across its entire length, just as flat as possible. Mine's sagged a tiny amount (I estimate about 0.5mm over a 1 meter span) along it's length, between the legs, not at all along the width. Then again, I'm not sure I can expect much flatter over these spans from MDF.

I've been using contractor's blueprints for all my z-poxy and glue work lately. Just put a couple peices of tape over the staples. Tear off boogered up sheets to expose new! (I know not everyone has access to these)

Necessity is the mother of invention; use what you got!

Hi David,

This article might help with regards to leveling your bench.
PDF is attached also. Hope this helps!

Cheers!
Rick

I can help with this one.....and I am going to second what Todd said. It's not necessary to have a workbench top that is within 5 thousandths of an inch from end to end....in fact....I'll even go so far as to say that is 'ridiculous'. We don't operate high end machine shops. Where I get picky is when I measure the flatness at any given 24" section.....that's where I want it to be flat.

I use my work bench A LOT. I purchased a Sjoberg top and made my own base because I viewed the base supplied as inferior. Here's how I flattened the top here recently. Take a granite plate, you can purchase these from Woodcraft for $30 dollars. Attach some PSA 80 or 60 grit to one side...lay it down on your top with sandpaper facing down....double stick tape some sort of handle to the top of the granite....and start excercising. See attached photos. Keep in mind these granite plates are very very very very very flat.

You will see some red chalk lines on the back of the bench....I did the whole work bench that way and started sanding until I couldn't see the chalk....did this process twice. You will get winded...but you'll also get an EXTREMELY flat bench. I didn't take enough off of the top to get to the chalk on the back. My bench was WAY out of flat....been 5 years since I did anything to it.

Here's the kicker....I can take a 24" steel machinists bar.......which has less than .0008 runout the entire length.....and at any given 24" position, perpendicular or parallel, I can measure no more than .0025 thousandths of an inch with feeler gauges anywhere I place the bar. I love my bench....

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There is no difference between the man that thinks he can....and the man that thinks he cannot.

As one of those guys in the high precision machine shops...I use a piece of surplus counter top from the hardware store for my 'bench'. If you want something big and really flat, buy a 2' square of 1" acrylic plate. Your bench will move, over time, more or less forever.

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Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services

I use Danish oil on my wooden bench tops, I think it works great for this.

As has been mentioned, wooden bench tops will move with humidity fluctuations, stress release, and just from general use, and may need relevelling. I use winding stricks to check for twist and hand planes to bring it back to shape. I don't know how flat it is (or how flat is flat enough), but for a reliable true reference surface I use the jointer bed or the table saw top.

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Rian Gitar og Mandolin