contact cement for laminating a bench top

[Jim Barstow]

I'm about to build a new top for my bench. The original bench top was built quickly since it was for a new shop in a new house and I had to bootstrap the entire shop. I couldn't spend a lot of time building a bench top when I didn't have a bench to work on. I ended up laminating 3 layers of mid-grade (no knots) 3/4 plywood by screwing them together (no glue). The end result is functional but ugly. I neglected to track where the screws were so putting in holes for bench dogs has been problematic.


This has worked well for 6 years while I've built most of the furniture for the new house but it's time for a new top.


I have no interest in building a top that qualifies as fine furniture. I've never viewed a bench top as fine furniture; to me it's a tool. What I'd like to do is do the same thing again, laminate plywood, but with much higher quality material and a better technique: 3/4" apply ply, and a nice solid wood edge


Ideally, I'd use a vacuum press to glue the 3 layers of plywood together. I have a vacuum system but my bag isn't big enough. The cheapest bag big enough is over $140 from veneer supplies.com. I really can't justify that much money for use only once.


The question is, can I just use contact cement? I've used contact cement several times for attaching formica to work surfaces and never clamped it. Seems like I should be able to use it to laminate the 3/4 ply. Once they are in contact, with a surface area of over 20 sq feet, I can't imagine the layers moving.


Anybody try something like this?

[Ian Scofield]

What about gluing them together but using a bunch of cauls to distribute the pressure? Not vacuum sealed pressure, but can get somewhat close

[Mel Fulks]

Agree with Ian. Put glue on BOTH surfaces, it will do fine and be permanent. Contact cement is not permanent, ask the
people who make it.

[Jim Barstow]

I researched the possibility of using cauls and came across horror stories of it just not working very well. For a lamination of this size (39 x 80), a vacuum press is rally the way to go. Problem is, the cheapest quality bag that will handle this size is already $140. If I went with the same quality as my smaller bag, it would be well over $200. I just can't justify that for a single use.

I'm not sure I accept the idea that contact cement is not "permanent". I've used it several times to attach formica to work tops (like a router table top) and it has lasted for, literally, decades.

[Mel Fulks]

Aha! The old pop quiz! Stuff was being glued a long time before vacuum bags. Contact cement sometimes lasts a long
time, mfgs. Will tell you it is less permanent than glue, I have already asked them. Good luck.

[Phil Thien]

I researched the possibility of using cauls and came across horror stories of it just not working very well. For a lamination of this size (39 x 80), a vacuum press is rally the way to go. Problem is, the cheapest quality bag that will handle this size is already $140. If I went with the same quality as my smaller bag, it would be well over $200. I just can't justify that for a single use.

I'm not sure I accept the idea that contact cement is not "permanent". I've used it several times to attach formica to work tops (like a router table top) and it has lasted for, literally, decades.

I agree that cauls would be an impossible challenge given the surface area unless you got the glue spread just right.

I wouldn't hesitate to use the contact cement.

[Dave Zellers]

Contact cement will be fine. Use 2 coats on each surface before joining. Follow the drying time for each coat carefully.

Make a surface on the floor as flat as you can. Assemble the panels there and walk on them to apply pressure. Pay particular attention to the edge all the way around.

[Richard McComas]

I have this crazy idea where you use both contact cement and wood glue. Layout on the sheet and put strips of masking tape on the plywood. Apply contact cement to the surfaces. Pull the masking tape while the contact cement is drying. Apply wood glue to where the masking tape was and press together. The contact cement acts as clamps and the wood glue is the permanent bond.

[Justin Ludwig]

Contact cement and screws. Layout your screws in a grid. Laminate one layer, remove screws after cement is dry. Rinse lather repeat for next lamination. Screw holes will be on bottom (or left in place on last piece) and you'll know where they are when you drill bench dog holes. You said functional, not pretty. I'm all about "Ugly Betty" tools.

[Jim Matthews]

+1 on this method.

I don't like having metal in my bench.
Prospecting isn't one of my hobbies.


FWIW - I would just use contact cement, glue up slightly oversize
and trim to the desired dimensions when everything is set.

[Pat Barry]

Seems to me that all you need to do is glue on a new, thin sheet of MDF and, yes, use your contact cement to do it.

[David Dockstader]

You know, you can buy an awful lot of cement blocks for a lot less than $140. Just cover it with cement blocks. If that's not enough, add a second layer. That should provide more than enough pressure to hold the glue and the pressure will be distributed very evenly. And then you can reuse the cement blocks. I prefer simplicity to technology.

[Morey St. Denis]

If it were me, believe I'd likely use a two-part phenolic-resorcinol resin for wood. It most closely matches the chemistry of adhesives used for bonding LVL and the multiple veneers of exterior grade plywoods. One part is a dark liquid the other is usually a Magenta colored fine powder, such as with DAP WeldWood 2 part Waterproof Resorcinol Glue. Be aware that you can significantly extend the working "pot-life" of most 2-part liquid glues up to nearly 4 hours by working in cooler ambient temperatures and keeping those two canned components refrigerated and by mixing right out of the freezer.

If you can easily remove the bench top and you're comfortable with existing flatness of the dry laminated plywood top, I'd likely make up my own larger vacuum bag by carefully splicing heavyweight gauge garbage bags together with plastic packaging tape. Securely drawing a uniform vacuum can be assisted by enclosing some textile cloth or polyester batting while incorporating twisted cordage around the perimeter, thereby effectively mimicking evacuation pathways & channels provided in textured commercial vacuum bags. As you mentioned having a working vacuum pump system, suggest you make use of it!

[Peter Kelly]

Roller or spray solvent-based contact cement on mating surfaces, allow to dry, bond. Weights not necessary. Have built lots of tops this way myself.

If you decide to go with PVA glue, roller on to one surface and bond and screw together. Remove screws after 60min and laminate.

Use brass screws if you're concerned about adding any fasteners and not removing them.

[Reinis Kanders]

Today on his blog Don Williams has a picture of a big lamination with cauls. Might be of interest. Screws from the back also should work with regular PVA.
http://donsbarn.com/of-studley-slabs...ican-mahogany/