Woodworking Talk banner
1 - 16 of 16 Posts

·
Registered
Joined
·
119 Posts
Discussion Starter · #1 ·
I just finished construction of a new work table for my shop. I was very particular to make sure that all my boards were true and that all of the legs were the exact same length. However, I knew there would be some give because my shop has a plywood floor and it is FAR from level and true. Not only that, my sheets of mdf did not line up well at all!

What is the best (and quickest) way to level the surface? I have seen some great jigs with a router sled, but honestly, it would probably take me 10 hours with a 5'x8' table and I really do not want to consume that much mdf dust in my lungs. Maybe a self leveling epoxy? What is your advice?

Thanks!





 

·
where's my table saw?
Joined
·
29,623 Posts
looks like a lack of braces underneath

If that's case, I would locate some 2 x 6's underneath on the flat and screw the mismatched surfaces down flat. There is no way to "surface what you have without "tons" on dust. You have to level what you have from underneath ....THEN add another layer of ply or particle board running opposite your seams. I would use Liquid Nails or other construction adhesive and weight to hold down the center. Unless there are enough braces underneath, the weights will cause the center to sag.... another reason to add more. When adding braces, put the concave side up to allow for future sag, if possible.

If you can remove what you have for top surface and rebrace at the seams that would be the easiest. That's a large table and you need as many braces as you can add. If not, you have to work from the underside, not impossible, just not easy. The top rails should be 2 x 6 for that size. If you can add a perimeter of them that will help. You can run them inside your 2 x 4's if you don't want to add to the outside dimensions. Then run some across or down the length every 18" or so. Basically I'm saying you've underbuilt the top frame and need more supports.

How about a photo of the underneath?
 

·
Registered
Joined
·
20 Posts
I can't really make out what your problem is. You seem to be saying that the table is not level because the floor isn't level. If that is the case, I'd suggest some leveling legs such as these:

https://www.mcfeelys.com/product/HDL-0620-MCF/38quot--16-x-2quot-Heavy-Levelers-10-pack

The other problem you seem to be experiencing is that the edges of the MDF panels are not flush. To fix this, I'd suggest, as others have, that you add blocking to the underside of the table under the joint. Then I'd suggest topping that with a piece of 1/8" unfinished hardboard and wrapping the edges with some 1x material to dress it up.

As others have also pointed out, you are stretching the capacities of the 2x4 frame with the length. You may be fine if this is a light duty bench but may have problems with putting a lot of weight on it. I just looked up the floor joist span charts and a SPF 2x4 is only allowable for a 6'1" span as a floor joist. I would suggest either replacing the long rails with 2x6 or adding a 2x3 directly below the current 2x4 with predrilled screws running vertically thru the 2x3 into the 2x4 as well as the screws into the legs.
 

·
Registered
Joined
·
269 Posts
Why does it need to be dead level? Flat yes, but as long as the table doesn't rock, I don't see a reason that it needs to be precisely level?

And what happens when you move the bench 12" to the left, it'll be on a different part of the floor, and won't be level again...
 

·
Registered
Joined
·
13,238 Posts
The last two posted comments are my thoughts exactly.

Even if for some reason you just have to have the table top exactly level with gravity I would not approach it by trying to plane the top. I would use leg levelers as shown by Dustin.

George
 

·
where's my table saw?
Joined
·
29,623 Posts
the photos tell all

the top is not flush, flat, level whatever... the top pieces are not aligned flush or flat. I don't think the table needs "leveling" screws on the legs ....I could be wrong. :blink:

Here's a great way to solve this problem., my opinion of course.
Make a "torsion box" top. This will solve the "sagging" issue I see in the photos and will make for a strong and flat surface for assembly.
http://americanwoodworker.com/blogs/projects/archive/2009/03/04/tom-s-torsion-box-workbench.aspx


I would use 1 x 3's laid out in a grid and leveled to the existing top AFTER it's been made as flush and flat as possible and braced underneath.
I would drill holes in the cross pieces so that 3/4" pipe can be inserted across the width in various locations, just in case you wanted to clamp something against the sides of the bench. It won't cost anything to drill the holes, but just make certain they are oversized and line up.
My assembly/outfeed table is made exacty like that and is covered with 3/4" particle board glued to the top and bottom. It is very strong and flat. However, I did not think of drilling the holes until afterward, and then it was too late. :thumbdown: I have a sacrificial 3/4" piece on top of that which I finished with shellac and it's held up really well. t's time to flip it over soon.

This may make the bench too tall, so just remove the necessary amount from the legs.
 

·
where's my table saw?
Joined
·
29,623 Posts
My torsion box build

Why not make a torsion box using 2 sheets of 3/4" particle board to make my outfeed table, about 9 ft 8 in by 30 inches. I used kitchen counter top stock to get the 10 ft particle board from a plywood supplier.
I spaced the pieces apart using four straight 1 X 3's and glued them on one surface. Then spaced cross braces in between and all along the length. Then spread glue on all the edges and plopped the top on and weighted it down. :yes: Pretty darn flat and man it is stiff and strong.
Attached Thumbnails
 

·
Registered
Joined
·
20 Posts
the top is not flush, flat, level whatever... the top pieces are not aligned flush or flat. I don't think the table needs "leveling" screws on the legs ....I could be wrong. :blink:
The OP mentioned that there would be some give because the floors are not level and true, the leveling screws on the legs would solve this. That should be addresses first. The lags are the foundation of the table, just as with a house if the foundation is off, everything else is off. The gap may be because the frame of the table is racked by the unlevel floors.

Another possibility is that there is a slight crown up in the 2x4 frame for the top and the gap is caused by the differing angles each piece of mdf is at as it meets the other.
 

·
Registered
Joined
·
119 Posts
Discussion Starter · #10 ·
I thank everyone for taking the time to reply to my questions. The pics were great, wish I would have thought of that.

I was thinking, "how hard can it be? Bulid a solid frame and slap some MDF on it....all done." One of the MDF sheets were warped or bowed a little. I couldn't tell until I placed the two sheets on the base to mark my studs for the brad nails. I figured that while I am on the table (hands and knees) it would flatten to the base below it when I nailed it down. But ... I was wrong.

Unfortunately, I was "wrong" AFTER I splattered some titebond 3 all over and nailed it down! So what is there....is there. I think the base structure is sufficient. The longest run for the 2x4's is 5' (the sides). On the long part of the table, they are almost 8' long, I cut them down to accommodate the side 2x4's. But the frame was all screwed together.

So when I up-righted the table after screwing all the legs on, I noticed some big differences in the top of the skirts vs. the legs. So I then adjusted the skirt to sit flush with the legs. Not sure of a better way to do this.

THE MAIN REASON for making such a monster is to be able to fit-up large pieces on a reasonably flat surface. So my projects do not turn out like this table...LOL!!!!! I could care less about "level"...flat is what I am after.

Here some pics of the bottom as requested...Thanks again guys!


Here you can see the side bracing...^^^^^^^^^^^^^^^

Here is the bottom side...vvvvvvvvvvvvvvvvv


:boat:
 

·
where's my table saw?
Joined
·
29,623 Posts
OK, got it

Instead of trying to remove the high stops or uneven places I would add leveling strips and shims to what you have and add another layer of particle board. That will be easier, less dust, less hand work and stronger. It will be thicker which will help also.
The strips can be as thin as 1/8" to make up the difference or if you want 1/2" thick for greater thickness. You will need to make strips of varying thickness to level out or build up to make it flat.

You will also need a long straight edge to run diagonally to check for flat before adding the top layer. When the straight edge will lay flat across all the shims along the edges and diagonally you will be close. The shims can be strips for around the edges or leveling pads in the center. I would use a strip where the seams meet for support.

I suppose you could handplane the high spots off the existing top but having done that on a large countertop myself, it was a pain in the rear. I had to have a totally flat surface to support the solid surface material, Zodiac. I used a handplane and a powerplane ...made a lot of shavings and dust...oh well. :eek:
 

·
Old School
Joined
·
24,017 Posts
I thank everyone for taking the time to reply to my questions. The pics were great, wish I would have thought of that.

I was thinking, "how hard can it be? Bulid a solid frame and slap some MDF on it....all done." One of the MDF sheets were warped or bowed a little. I couldn't tell until I placed the two sheets on the base to mark my studs for the brad nails. I figured that while I am on the table (hands and knees) it would flatten to the base below it when I nailed it down. But ... I was wrong.

Unfortunately, I was "wrong" AFTER I splattered some titebond 3 all over and nailed it down! So what is there....is there. I think the base structure is sufficient. The longest run for the 2x4's is 5' (the sides). On the long part of the table, they are almost 8' long, I cut them down to accommodate the side 2x4's. But the frame was all screwed together.

So when I up-righted the table after screwing all the legs on, I noticed some big differences in the top of the skirts vs. the legs. So I then adjusted the skirt to sit flush with the legs. Not sure of a better way to do this.

THE MAIN REASON for making such a monster is to be able to fit-up large pieces on a reasonably flat surface. So my projects do not turn out like this table...LOL!!!!! I could care less about "level"...flat is what I am after.

Here some pics of the bottom as requested...Thanks again guys!


Here you can see the side bracing...^^^^^^^^^^^^^^^

Here is the bottom side...vvvvvvvvvvvvvvvvv


:boat:
You could do better with more of a grid under the top. The floor will continually present a "level" problem. Adding adjusters to the legs would simplify keeping the table flat.







.
 

·
Sawdust Maker
Joined
·
189 Posts
Just for the record. Flat and level are two different things. First you need to build a table that is square and flat. Then level the table to accommodate the uneven floor. If the table was not built flat, no amount of leveling is going to make it flat. All the info to do those two things have been posted above.

I believe a torsion box is your best bet for a top that big. You did not mention what this table will be used for or how much weight it needs to support. When a top needs to be flat, it also needs to remain flat while under load. That will play a major role in the tables design.

Look in my album. I needed a table that was flat, and would remain flat with 1000 pounds of weight in a 2' x 3' area. That was my solution and it works very well.

Mike Darr
 

·
Master firewood maker
Joined
·
1,973 Posts
1 - 16 of 16 Posts
Top