I don’t know where to post this and I’m sorry if it’s in the wrong place. I just wanted to ask what is your faith that a piece of 3/4 plywood that overhangs an edge and is unsupported there after won’t cup upwards. It will protrude outwards less than 2” and run along the side of the bench for about 7 inches, and be unsupported anywhere in that area, relying on its own stiffness to hold it flat. What makes me worry that it may cup upwards is that this is part of a workbench top and it will be bolted to the supports centered at 2 3/4 back from that outermost edge. Will the pressure from the bolts cause the edge to rear up? This is a single layer thick top.
Duane Bledsoe
Plywood edge curve
Quality plywood won't move for those dimensions...
how many ply plwood are you using and what type/species...
how many ply plwood are you using and what type/species...
Honestly don’t know what kind. I went to Home Depot and bought a sheet that was completely clear on both sides of any blemishes. The veneer seems soft though, really soft texture wise, almost like touching suede leather.
As for plys, there are 5, plus the thin veneers. It is 3/4 thick.
Only mark I see is in the edge and it says GRADO B
As for plys, there are 5, plus the thin veneers. It is 3/4 thick.
Only mark I see is in the edge and it says GRADO B
There’s a mark beside the words that either could be a letter A or a black triangle. Can’t tell. It just looks like this:
A GRADO B
A GRADO B
I think you will be OK. It would be even better if you used a higher quality plywood with more layers.
I have built birch plywood cabinets and didn't want the end grain to show, so I made 3/4 X 3/4" strips of solid soft maple (has a similar grain and color of birch), then covered the plywood end grain with these strips. I used biscuits and glue to attach them and then a flush trim router bit to trim them even with the plywood surface. Doing this not only covered the plywood end grain, but also strengthened the plywood edges and helped prevent the plywood from warping, kind of like a breadboard edge on a table, so it might be worth doing. Cross grain gluing isn't a problem when doing this, because of the stability of plywood. I have never had one of these joints fail.
The A Grado B means that one side is A grade and the opposite side is B grade. A grade is a smooth unblemished surface. B grade can have minor blemishes, but the surface is smooth. Sometimes they patch knots and blemishes to make the surface smooth. This is acceptable for a grade B surface, but not for a grade A surface.
If you bought this plywood from a big box store, the surface veneers are likely paper thin, so do as little sanding as possible or you might sand through the surface veneer. The higher the quality of the plywood, the more internal layers it will have and the flatter and more stable it will be. The plywood called "Baltic Birch" will have many thin layers and no internal voids in any of the layers, so it is more stable than plywood with fewer layers and internal voids, but true Baltic Birch plywood is metric dimensioned and about a 60" X 60" sheet size.
Charley
I have built birch plywood cabinets and didn't want the end grain to show, so I made 3/4 X 3/4" strips of solid soft maple (has a similar grain and color of birch), then covered the plywood end grain with these strips. I used biscuits and glue to attach them and then a flush trim router bit to trim them even with the plywood surface. Doing this not only covered the plywood end grain, but also strengthened the plywood edges and helped prevent the plywood from warping, kind of like a breadboard edge on a table, so it might be worth doing. Cross grain gluing isn't a problem when doing this, because of the stability of plywood. I have never had one of these joints fail.
The A Grado B means that one side is A grade and the opposite side is B grade. A grade is a smooth unblemished surface. B grade can have minor blemishes, but the surface is smooth. Sometimes they patch knots and blemishes to make the surface smooth. This is acceptable for a grade B surface, but not for a grade A surface.
If you bought this plywood from a big box store, the surface veneers are likely paper thin, so do as little sanding as possible or you might sand through the surface veneer. The higher the quality of the plywood, the more internal layers it will have and the flatter and more stable it will be. The plywood called "Baltic Birch" will have many thin layers and no internal voids in any of the layers, so it is more stable than plywood with fewer layers and internal voids, but true Baltic Birch plywood is metric dimensioned and about a 60" X 60" sheet size.
Charley
I looked it up on the HD website and it’s called Sande plywood (not sanded but Sande).
I thought I was buying Purebond when I got it. Guess not. Oh well, it’s a mobile workbench, not an heirloom. Just has to work, and if it gets skinned up (cause this surface takes dents and scratches easily) then it will just look more the part.
I’m making a (takes a deep breath and sounds like Ralphie in The Christmas Story) mobile workbench/table saw infeed-outfeed/router table/jobsite sawhorse/sanding platform/miter saw station/small projects assembly and finishing station........phew!
I’ll post pics when it’s done. Right now I’m drawing designs.
I thought I was buying Purebond when I got it. Guess not. Oh well, it’s a mobile workbench, not an heirloom. Just has to work, and if it gets skinned up (cause this surface takes dents and scratches easily) then it will just look more the part.
I’m making a (takes a deep breath and sounds like Ralphie in The Christmas Story) mobile workbench/table saw infeed-outfeed/router table/jobsite sawhorse/sanding platform/miter saw station/small projects assembly and finishing station........phew!
I’ll post pics when it’s done. Right now I’m drawing designs.
I dunno, Duane...anything that big isn't gonna be so mobile... 
I would think you won't have problems with those dimensions...but consider exposure to sun, liquids, rain, un-level surfaces, and other plywood-toxic stuff in using the plywood you have. Dings, scratches, dents, cracks in the external veneer, etc... will affect its performance over time. Look at it this way...it will require maintenance and replacement because it's inevitable that you will need to use it outside, in the cold, in the rain, in the humid, etc...
Best...looking forward to the pics...
I would think you won't have problems with those dimensions...but consider exposure to sun, liquids, rain, un-level surfaces, and other plywood-toxic stuff in using the plywood you have. Dings, scratches, dents, cracks in the external veneer, etc... will affect its performance over time. Look at it this way...it will require maintenance and replacement because it's inevitable that you will need to use it outside, in the cold, in the rain, in the humid, etc...
Best...looking forward to the pics...
Duanne, what is the overhang going to be used for?
On a previous work bench, I had an over hang of 1 1/2 inches. Then I attached a second piece underneath the outside edge to make it 1 1/2 inches thick. Then I added an edge piece made of oak all around the top. So, I wound up with two inches overhang and strong enough for clamping purposes.
Just something for you to think about if it would work into your plans.
Mike
On a previous work bench, I had an over hang of 1 1/2 inches. Then I attached a second piece underneath the outside edge to make it 1 1/2 inches thick. Then I added an edge piece made of oak all around the top. So, I wound up with two inches overhang and strong enough for clamping purposes.
Just something for you to think about if it would work into your plans.
Mike
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Well the overhang was actually going to be used for clamping. I don’t have room to add an additional piece to thicken it, nor add any hardwood. This is for use on an old miter saw stand, making use of the old frame to make a mobile work bench. The way it is made prevents anything else from being done in this area.
It may be me just overthinking things by even doing this. I was trying to engineer clamp ability on all four sides. I can clamp along the edge of the two longer sides, and most likely would never have a need to clamp on the two shorter sides, but I can’t get past the “what if” part of it.
It may be me just overthinking things by even doing this. I was trying to engineer clamp ability on all four sides. I can clamp along the edge of the two longer sides, and most likely would never have a need to clamp on the two shorter sides, but I can’t get past the “what if” part of it.
If you are worried about the soft surface, a piece of 1/4" Masonite (tempered MDF) on the top will take all kinds of punishment, and if you attach it with flat head screws, it can be replaced if you should ever feel the need to. The tempered version of mdf is quite hard and will not break easily if backed by plywood. It's quite reasonably priced too.
Another option to consider is using an industrial solid core door for a workbench top. They are HEAVY, but hold up incredibly well when used as a workbench top. Some are solid wood with a veneer on both faces, while others are mdf in the middle with solid wood edges to hold the hinge screws and door knob and 1 3/4 to 2 1/2" thick. If you trim it to eliminate these areas and it has an MDF center, just screw and glue a hard wood strip to cover the bare MDF edge.
Some years ago in my former workshop I had a workbench with a top made from one of these doors (2" thick). I left it there because it was too heavy for me to get out of the basement shop, even with a good friend helping me, but I still miss having it 35 years later. That was a very solid workbench.
I recently saw a brand new commercial door for sale at my local Habitat Store for $50. It would cost 3X that much or more to make a bench top as solid as that door from anything else. The legs of my old bench were just 2 X 4 construction lumber screwed and glued together. Nothing fancy, but solid as a rock.
My present shop is too small for a work bench like this or I would have come home with that door and made new bench from it. I still miss that old re-purposed door work bench.
Charley
Another option to consider is using an industrial solid core door for a workbench top. They are HEAVY, but hold up incredibly well when used as a workbench top. Some are solid wood with a veneer on both faces, while others are mdf in the middle with solid wood edges to hold the hinge screws and door knob and 1 3/4 to 2 1/2" thick. If you trim it to eliminate these areas and it has an MDF center, just screw and glue a hard wood strip to cover the bare MDF edge.
Some years ago in my former workshop I had a workbench with a top made from one of these doors (2" thick). I left it there because it was too heavy for me to get out of the basement shop, even with a good friend helping me, but I still miss having it 35 years later. That was a very solid workbench.
I recently saw a brand new commercial door for sale at my local Habitat Store for $50. It would cost 3X that much or more to make a bench top as solid as that door from anything else. The legs of my old bench were just 2 X 4 construction lumber screwed and glued together. Nothing fancy, but solid as a rock.
My present shop is too small for a work bench like this or I would have come home with that door and made new bench from it. I still miss that old re-purposed door work bench.
Charley
While you look at the pics I'll explain. There are two mounts attached to the rails of the stand, one on each end, and they can be moved any distance apart or together. Currently they are in the farthest position apart. They also don't even have to be used. The plywood overhang I was going to ask about would be about 2 inches passed where the mounts stop, and theyre so close to the surface below where the extension latches are at that I cannot add any extra to thicken the edge. I can move the mounts closer together to make this problem go away but the tradeoff is a downsized surface from 36 inches to 30 inches to allow barely enough room on each end to get clamps in place between the new top and the metal frame. I could also simply make the work surface taller to fix it and not lose work space but then I give up using it as a infeed/outfeed table for my tablesaw. So based on this, the work surface space and table saw feed uses are more valuable to me than end clamping during any project.
When I built my latest router table with a single layer of mdf for a top I left an overhang on all sides for clamping and it will be no issue for what you want to do. I added build-up under the edges but that was only so I could add a hardwood edging to it and I wanted more contact area to glue it to than just the 3/4 thickness. I also agree with adding something hard and slippery to the top if you plan on using it as an infeed/outfeed. I capped my RT with HPL.
That looks like a good candidate for a portable top like I have. Mine is 3/4 inch mdf.
Modify some HF clamps and drill dog holes in the top to provide all sorts of clamping possibilities. Mine has worked great so far.
HF Clamp mods...
http://www.routerforums.com/show-n-tell/105529-clamp-mods.html
Portable work top.
Modify some HF clamps and drill dog holes in the top to provide all sorts of clamping possibilities. Mine has worked great so far.
HF Clamp mods...
http://www.routerforums.com/show-n-tell/105529-clamp-mods.html
Portable work top.
Attachments
Stick's advice is good. I would definitely add a 1/4 inch Masonite on the top, screwed in place, not glued, so you can replace it easily. If you are going to use that lip for clamping (as I would and do), then I would seriously consider gluing a second edge of good ply or even better, a good flat 3/4 to 1 inch pine under the top. The extra thickness will support the vise very well and keep the edge flat. I would actually glue this on and add a few screws to lock it in place while the glue dries. The edge of my bench is almost 4 inches thick, using the method I described, and it's both flat and strong.
My table is from Harbor Freight, so the top is actually 3/4 thick with about a 3 inch Maple lip around the top. I used 1 inch pine to build up the edge, so the pine I placed under that lip is about 2 1/4 inches wide. Because the lip is really thick (three layers), I was able to put a fold down section behind it. Because the table has drawers directly under the top, I didn't add a front vise. But today I'd sacrifice one drawer to put a vise there. A front vise is wonderful for working with a hand plane. So your thickening the edge can be selectively extended under the top to allow you to add a front vise in the future. Adding a few strips of hardwood as trusses will give you years of extra service.
My table is from Harbor Freight, so the top is actually 3/4 thick with about a 3 inch Maple lip around the top. I used 1 inch pine to build up the edge, so the pine I placed under that lip is about 2 1/4 inches wide. Because the lip is really thick (three layers), I was able to put a fold down section behind it. Because the table has drawers directly under the top, I didn't add a front vise. But today I'd sacrifice one drawer to put a vise there. A front vise is wonderful for working with a hand plane. So your thickening the edge can be selectively extended under the top to allow you to add a front vise in the future. Adding a few strips of hardwood as trusses will give you years of extra service.
I had a piece of the ply I think you are using. To my dismay, it had a center layer of strips of bamboo. Split, separated, splintered like mad. Hate the stuff, who ever bought it at HD should be fired. Now stick to Baltic Birch as much as possible.
Even though you're repurposing the stand, you can use almost all the suggestions to make the top.
Even though you're repurposing the stand, you can use almost all the suggestions to make the top.
Duane I'd repeat everything Oliver said to you word for word. If you are worried abiut the plywood de-laminating to some extent and not being flat after then follow his earlier advice to add masonite. Carefully countersink the screws so that they are just below the surface and when you place the screws drive them into solid wood cross members below the top. That will eliminate any chance of de-laminating. Like Oliver said, it's only a work top and you'll learn from it if it works or doesn't work. Usually tops can be replaced without starting over from scratch so use what you got and see what happens.
If you use the masonite top, give it a coat of wax so glue sqeeze out doesn't stick. Gaffboat is right about the plywood.
Hey Duane - I put less thought into buying a new car than you do into a router table top :grin::sold:. Just do it - Merry Christmas
I once had an employee who over analyzed everything. It was an always “what could go wrong” mentality kept him from going forward with a project. Spent ten times more time worrying then actually doing, never accomplished anything.
In woodworking there is always more then one way to accomplish something.
In woodworking there is always more then one way to accomplish something.
Duane the comments being made border on being unkind but they are honest. I don't mean this in an unkind way and all the latest comments have been made to be helpful but you seem to suffer from a human condition known as "analysis paralysis". You worry so much about doing something wrong that you have difficulty doing anything at all and the only guaranteed way to fail is to not try (or do nothing).
Here is the problem put into perspective. You will be using about 1/4 of a $40 sheet of plywood. If designed properly the top will be replaceable. Any problems not anticipated may be fixable after the fact. Problems not fixable with the original top can be fixed by replacing the top with a different material in this case for a roughly similar cost. This seems to be the factors that were missing from your original analysis. This is a potential $10 mistake at it's worst possible outcome.
Here is the problem put into perspective. You will be using about 1/4 of a $40 sheet of plywood. If designed properly the top will be replaceable. Any problems not anticipated may be fixable after the fact. Problems not fixable with the original top can be fixed by replacing the top with a different material in this case for a roughly similar cost. This seems to be the factors that were missing from your original analysis. This is a potential $10 mistake at it's worst possible outcome.
Duane, Chuck is right, after all those work tops you have built for your shop in the past shows you know what you are doing. I think you should use some tempered Masonite on top of the plywood too like you did on the workbench, mitersaw table and the other tops you built for your shop. That would solve any de-lamination problems that might occur,and give you a nice smooth top.
Herb
Herb
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