# substrate for laminate countertop that will see freezing temp



## sillyburt (Mar 16, 2001)

I plan on making a laminate countertop for a cottage. Cntrtp is L shaped and I cannot make it without a seam nor can I put the seam thru the sink. So I will have a full length (width of cntrtp) seam.

My question is what would make a better substrate for the countertop considering it will be closed for the winter and see below freezing temps. It could see as low as 0 degress or less and I cannot build the countertop without seams. Im afraid this will play havoc on the seams.

Cost of substrate is not an issue -within reason. That is, Im considering between MDF, particle board or possibly even plywood. The cost between these materials is not an issue but I dont know which would be best for the huge temp swings the place will see between summer and winter.

Any help, suggestions or prior experience with a situation like this would help.


----------



## MEL (Jul 17, 2005)

I would look at an Industrial grade particle board. Not the stuff from H.D. or Lowes, but a TRUE industrail grade. All America Plywood in Detroit, Bond Plywood in Ferndale or Plywood Detroit in Warren can poin you in the right direction to buy their Industrial board.


----------



## tdf (Feb 10, 2006)

pboard, mdf, marine grade ply. depends where you are using, how long, weight, etc.

PM me if you have any ?'s.


----------



## sillyburt (Mar 16, 2001)

tdf said:


> pboard, mdf, marine grade ply. depends where you are using, how long, weight, etc.


using in kitchen, 9.5' x 7.5' sink is in 9.5' length and cannot be moved due to window placement.

my main concern is what will happen to countertop when cottage is winterized and temps get below freezing?


----------



## jpollman (Jan 14, 2001)

Don't use mdf!

Also, don't buy your particle board at HD or Lowes. There's a place on Baldwin Rd. just north of Walton called Pontiac Plywood. There's where I get all my materials. If you go there you can get high density particle board that's designed for counter top substrate. The nice thing about that place is they carry it in standard 8, 10, and 12' lengths. But you can also get it in 25", 31", 36" and 48" widths. That's a big time saver. Get the 25" and you just have to rip down some 1-1/2" strips for the edge doublers and some square blocks for the corners and you're all set. 

You shouldn't have any trouble with the temps I'd think. When I seam a counter top I put three or four "biscuits" in the seam. I also use draw bolts. When I assemble the counter top I put glue on the biscuits and insert them and then along the seam. Then usually three draw bolts along the seam. Clamp it up and when the glue is set it isn't going anywhere! I see you're in Oakland County but don't know where. If you want to try draw bolts I've got some you can have. I bought a case of them years ago when it looked like I was going to get the counter jobs for a number of new tire stores. Well I did the first two and then they never opened any more so I've got more than I'll probably ever use. If you're in the Rochester area, drop by and I'll give you a few.

John


----------



## jpollman (Jan 14, 2001)

I just had another thought. If you do a good job when you use the contact cement and do the laminating you shouldn't have any trouble with those temps. Now I know this isn't zero degrees but I've built display units for floral coolers for years. There's one I built over twenty years ago and it's been in the cooler at basically 38 degrees 24/7 all this time and the laminate shelves are still in great shape. And that's in a very moist environment too.

John


----------



## sillyburt (Mar 16, 2001)

jpollman said:


> When I seam a counter top I put three or four "biscuits" in the seam. I also use draw bolts. When I assemble the counter top I put glue on the biscuits and insert them and then along the seam.
> John


I was going to 'double up' where the seam for the substrate is. that is, the seam is going to be parallel and inside of the long sided portion L. the lasy susan is underneath that corner. I was basically going to make a cornered half lap joint with the substrate with screws. also the cabinets are cheap 'off the shelf' from HD and I have to add piesces to screw the substrate to the cabinets...thinking of using some wood angles liquid nailed in.

yeah I'm a few miles north of Pontiac Plywood. I called them about laminate sheets seme time ago.

are there any seams in the laminate sheets for the floral cabinet shelves? I know the lam sheet will expand/contract differently than the substrate and between dry 0' temps and humid 90+' temps I'm afraid the seam will open up. I was hoping for a material that would expand/contract just like HPL. HA LOL. I'm just concerned the seams will open up on the laminate.

some have also suggested shellacing underneath the sink ?

I've been reading a couple of books -Working w/Plastic Lam by Cliffe & Adams and also making plastic lam countertops by Kimball. Dman it's hard to find info on this stuff. the books have helped but everytime I think I'm ready 'to go' something else gets me guessing on this that or the other thing abouthow I should do it. if it was in a constant temp house I would've had it done by now :-s

thanks for input so far guys...


----------



## jpollman (Jan 14, 2001)

Whenever I do an L shaped counter I always just miter the joint. Each piece is cut at a 45 and that forms the 90. The substrate along each edge of the joint it doubled up to 1-1/2" and then I cut a slot at three places along the seam for the draw bolts. Then I cut the slots for the biscuits. These help align the joint and keep it flush. When it's all glued up and clamped with the draw bolts it's extremely strong. When the joint is all done and installed I'll usually run a small amount of clear silicone down the joint and clean it up. This seals it from water penetration. I've been doing it this way for years and never had a problem.

Back to your other question. No there are no seams in the shelves of the cooler unit I built. But because of the moisture issues with being inside the cooler I used a good quality oil based stain and sealed the back side and any unlaminated edges of the substrate. Plus because this is a walk in cooler, it made it look better and brightened it up in the back. 

John


----------



## ESOX (Nov 20, 2000)

Another reason to seal the back of your counter top, You will be hitting dew point daily spring and fall. The underside could potentially soak up water and swell on the wet side, causing a warpage of the HDPB and subsequent delamination of the laminate. 
Issues like that are the same reason why you never see just one side of a piece of wood veneered, if it is to be hidden, the back side will be veneered with a lower quality veneer just to equalize the rate at which wood gains and loses moisture due to atmospheric changes.


----------



## jpollman (Jan 14, 2001)

I wasn't thinking it would be necessary but ESOX brings up a good point about the moisture issue in your particular situation. It wouldn't be a bad idea to seal the back side of the counter when you're done fabricating it and before you install it. Go to HD or Lowes paint dept. and look at their "oops shelf". They've always got stains and paints that were mixed incorrectly so they put them there and sell them cheap. Color doesn't matter because it won't be visible. I would do the entire under side and the edges that aren't lamiated. It would be quick and easy to do before you install the top and would probably help a lot.

Good luck!

John


----------



## Kevin_D (Dec 3, 2005)

Don't put laminate seams over top of substrate seams.
Good idea to seal back side of substrate.
I don't think the temp variance will be a big factor.
As said before use quality products.
Have a fun project.


----------



## Formula31 (Feb 17, 2009)

High density particle board is right and also is the only thing that laminate makers will stand behind their product. I have had jobs that speced out lumber core birch but it is very expensive. Whatever you do with the change of heat and humidity and absorbtion rate you will get some movement. Make sure your adheasive is acclimated to the area that the top will be in. Acclimate both the substrate and the laminate in the same area for at least 24 hours. On large area jobs we like to prime the wood with a coat of adheasive to cut back on shrinkage. It helps a lot. Contact cement has a lot of drying agent in it. If all else fails buy a tube of Kampel SeamFil in the color of your laminate. Use the solvent that goes with it.


----------



## loonatic31 (Nov 12, 2008)

call a local "custom" cabinet shop,they should be able to point you in the right direction or do some digging on the internet,I have personaly never had a prob with MDF 3/4 and our place is in lake county and we have never had a prob and the counter has two seems!!


----------



## sillyburt (Mar 16, 2001)

thanks for insight and advice guys, very helpful.

I went to work on one of my 'goof' projects today, my router table. I went to pontiac plywood and picked up some sta'-put non-flamable (but still not water based) adhesive and I'm not sure if it was the consistency it was supposed to be. 

I did the edge side of the router table and that stuff was gooey and had a rubbery like consitency. after wiping it on I had some thick globs. don't know if that is how non-water based adhesive is supposed to be? could I have gotten some that was past its expiration date?

however it sure did hold the lam. it dried on both pieces to be attached together quickly, almost too quick.

I'm afraid when doing the top and bottom of the router table it will gum up on me while I'm spreding it on due to the top's large surface area?

again thanks for advice and help. I've searched on the internet and haven't been able to find this amount of help and experience with this stuff.


----------



## eddiejohn4 (Dec 23, 2005)

Why not contemplate using and making your own concrete counter top?


----------



## The_Don (Apr 28, 2008)

sillyburt said:


> thanks for insight and advice guys, very helpful.
> 
> I went to work on one of my 'goof' projects today, my router table. I went to pontiac plywood and picked up some sta'-put non-flamable (but still not water based) adhesive and I'm not sure if it was the consistency it was supposed to be.
> 
> ...


Get a cheap foam roller pour out a stream on the table and roll it out, instead of spreading it much easier. Yes contact cement is stringy stuff when you start moving it around.


----------



## tdf (Feb 10, 2006)

Jpollman has it right with the PB in the cold. We have stored casework and tops with pb core in below freezing without a problem. Sealing the bottom concealed side of the top with a balanced laminate is a good idea. Suppliers sometimes have laminate cover sheets or dunage they may give you to use as a liner balance sheet.

good luck


----------

