Gluing Cork Sheet to Plywood

[Pruitt]

I'm looking for suggestions about gluing cork sheet to plywood. 

I'm not talking about roadbed - I just use full strength yellow glue for that. I'm talking about gluing a sheet of cork to a sheet of plywood.

Yellow glue works, but it's a pain to spread on the bottom of the cork, and it uses a lot of glue. I tried diluting the glue to make it easier to spread and to not use too much, but sometimes that weakens the glue bond so that the cork isn't stuck well.

I've thought about using a spray adhesive like 3M Super 77, but I'm not sure how well that would work either. Will the bond be permanent, especially when the cork gets wet from scenery building?

Any thoughts? Suggestions? 

Thanks!

[peahrens]

I used the (thinner) cork sheet for my yard and simply used Alex Plus latex caulk, same as for my usual (HO) 1/4" cork mainline roadbed.  I applied the caulk to the plywood in "S" curves, spread it with a putty knife, laid the cork and put books on it over night.  Very easy. 

I would think the thicker carpenter's yellow wood glue would be tougher to spread, more expensive, etc.

I highly doubt that water from scenery building would cause any significant issue.  It was no problem with my scenery adjacent to my main roadbed nor my thinner yard cork.

[rrebell]

Yellow glue witll proubly be the best for this. You can buy really cheap disposable mini paint rollers for a couple bucks, comes with tray and handle, bought a few over the years for my landlording job.

[Pruitt]

peahrens

I used the (thinner) cork sheet for my yard and simply used Alex Plus latex caulk, same as for my usual (HO) 1/4" cork mainline roadbed.  I applied the caulk to the plywood in "S" curves, spread it with a putty knife, laid the cork and put books on it over night.  Very easy. 

I would think the thicker carpenter's yellow wood glue would be tougher to spread, more expensive, etc.

I highly doubt that water from scenery building would cause any significant issue.  It was no problem with my scenery adjacent to my main roadbed nor my thinner yard cork.

I use caulk for roadbed on foam. Didn't really think about using it for cork onto plywood. It would certainly address the concern of wetting the cork enough to cause the bond to fail, though.

rrebell

Yellow glue witll proubly be the best for this. You can buy really cheap disposable mini paint rollers for a couple bucks, comes with tray and handle, bought a few over the years for my landlording job.

I used a foam brush to spread the yellow glue on one sheet of cork. It was a pain because the glue is so thick (but it worked). Wouldn't the rollers have the same difficulty? And when I paint a room, a standard roller absorbs a lot of paint that you can't get back out. Don't the mini rollers do the same thing with the glue? I've never used one of those, though I do have a tray and a few of them my late wife had.

I'm thinking the putty knife might be a good option for spreading the yellow glue...

[jjdamnit]

Hello All,

You didn't mention how large an area you are dealing with.

Have you considered Contact Cement? That's what it is designed for.

It is pourable and you can use a wide putty knife to get a thin even coat.

You would cover both surfaces, and allow them to dry slightly- -until "tacky".

Mate the surfaces and apply pressure.

For best adhesion you can use a carpet roller, available at most hardware/home improvement centers. A large diameter dowel or purpose-bought rolling pin could be used too.

Hope this helps.

 

[selector]

I would use the DAP Alex Plus with Silicone, but I can tell you that the 'white' variety is vastly different from their 'dries clear' variety.  I dunno why, and I dunno if it's still the case, now 12 years after my first stab at doing what you're doing, but when the white stuff dried, it had very little adhesive power.  On the other hand, there's nothing like the 'dries clear' variety.  It retains a slightly rubbery feel and has very good grip.  

Just make sure it is spread well, not like paint, but with a narrow spatula to get the bead much wider in a squiggly pattern so that you get good control over a wide area under the mat.

[York1]

Pruitt

Will the bond be permanent, especially when the cork gets wet from scenery building?

 

This was a problem for me.  I covered a yard section with a cork sheet, and I used caulk.  What I didn't do was spread it evenly.  Later, when I put down ballast or scenery, I used alcohol and watered glue.  The result is that in small little sections, the cork absorbed the alcohol or water, expanded, and bubbled up.  Not fun.

I would imagine that whatever you use, if you spread it evenly, you can avoid that problem, but I'm not sure.

[tstage]

Mark,

I'm with Crandell.  I would go with the DAP Alex Plus Latex Caulk w/Silicone.

Tom

[Pruitt]

Thanks for the input, everyone.

In regards to area being covered, it totals out to roughly 25 square feet, or most of a sheet of plywood. The cork roll I'm using is four feet wide, and the plywood was basically split down the middle lengthwise and laid end-to-end. Here's what the area looks like:

I thought about contact cement, but the precision needed when positioning the cork to make the bond has me hesitant. Plus I only have a small tube of Pliobond that I use for turnout construction. I don't have a can big enough to do the area I'm working on.

I use the Dynaflex 230 caulk for sticking down track. As I said above, I really didn't think about it for a large sheet. In any case, I have about 1/2 of a tube left - like the contact cement, not nearly enough to do the entire area. What's the cure time like for a good bond in this application?

I glued down one roughly four-square-foot section of cork early this morning with the yellow glue, and it worked great! Spreading the glue with a brush was a bit of a pain though. I did a second section about the same size after my last post, using a six-inch putty knife. Much easier, though I still needed to use the brush to get the edges covered well. That's weighted and drying now. It would be easier if the cork didn't try to curl up from being on the roll.

So why is not having the caulk or contact cement on hand an issue? Well, yesterday I tested positive for covid. Very mild case, with basically just a bit of tiredness over the weekend and a cough I expect to linger for awhile. Caught it from my wife, who tested positive Friday. I have to stay home for five days per CDC guidelines.

So since I have the yellow glue on hand, I'll probably just keep going with that for now, and maybe try the caulk or contact cement on the next town.

[CharlieM]

I have had very good results with slightly thined yellow glue. Thinning makes it easier to spread and easier to remove later if you need to rework an area. I spread the glue with a 1" paint brush. Thin in a cup with just enough water to make spreading easier. No where near 50/50. You want to get an evan layer. Only work an area that you can keep wet and covered at one time. The thining does slightly weaken the bond, which is good. You will appreciate it when time comes to remoive the cork and do something different. Particularly applicale to track areas. Full strength yellow glue is way overkill. Be sure to weight down large flat areas for drying and use lots of push pins.

My experience with Alex caulk etc. is it adheres great but is harder to get on evenly and it shrinks. I've gone to using full strength yellow glue for my foam applications too. Re contact cement, I agree with your concern on precision placement. Once it's down it's down; no tweaking it. I'm just not that good.

[doctorwayne]

While I've not had need of sheet cork, I did put down some cork roadbed using gelled contact cement.

Other than complaints about the odour (from SWMBO - I can barely smell it at all), it worked great.
The advantage of the gelled version is that there's no stringiness during application.  I first discovered it over 30 years ago, when I was building kitchen cupboards for the house that I had just built.  (The cupboards were put together with screws, of course, but the finishing veneer was added with the contact cement)...none of it has ever loosened or warped - great stuff.

I've had conversations with a lot of people who don't care for contact cement, and the majority of them don't care for it because they don't bother reading the instructions on the can, which very clearly state:  brush on the contact cement, applying it to both surfaces to be joined, then let it sit until the cement is completely dry-to-the-touch, before bringing the two surfaces in contact.

If you're worried about aligning the two surfaces properly, use waxed paper to cover the non-moveable surface, leaving only one edge of it slightly uncovered.  You can then position one edge of the cork along that exposed area, pressing it into "contact".
You can then begin to slide the waxed paper away from the glued-in-place edge, following along by pressing the cork sheet onto the fixed surface, making sure to press it down firmly to avoid trapping air under the cork.

I've also used the gelled contact cement for putting-down Central Valley tie strips onto cork roadbed, and then used the same to secure the rails in place.

It sticks like you-know-what-to-a-wool-blanket

Wayne

 

 

[Doughless]

I have tried to do a similar task, and it seems that putting down the adhesive smoothly and uniform is difficult.  Rollers and brushes tend to cause peaks and valleys, or even voids, and the sheet cork would bubble up where the adhesive was too thin.

Thinning out the adhesive so that it spreads nicely also left thin spots.

I think spray adhesive would give the most uniform covering, but I've never tried it. 

[Pruitt]

And now a related question - anyone have any brilliant method of taking the curl out of cork that comes off a roll? 

The first sheet of cork I put down today curled downwards, which worked great. I weighted it across the entire surface, and the strain energy from the curling held the edges down tight. Perfectly flat when dried.

The second sheet curled upwards, and even though I weighted it too across the entire surface, the long edges where the cork was curling up didn't adhere well. It's not a big issue, but it's bothersome. So other than laying the cork out flat and weighting it for a week or two to mostly get it to relax, what practical methods are there to relax the cork within a day or two?

[BigDaddy]

I used diluted white glue with cork sheets on foam.  If you don't have complete coverage, you get the equivalent of bubbles, areas of cork, not glued and squishy when you push on them.

No idea how much I diluted the glue, I may have sprayed i with wet water.  Sheet cork can be pourous and the glue can come through the top side and stick to what ever you use to weigh it down.   Wax paper is your friend there.

[Doughless]

Pruitt

And now a related question - anyone have any brilliant method of taking the curl out of cork that comes off a roll? 

The first sheet of cork I put down today curled downwards, which worked great. I weighted it across the entire surface, and the strain energy from the curling held the edges down tight. Perfectly flat when dried.

The second sheet curled upwards, and even though I weighted it too across the entire surface, the long edges where the curk was curling up didn't adhere well. It's not a big issue, but it's bothersome. So other than laying the cork out flat and weighting it for a week or two to mostly get it to relax, what practical methods are there to relax the cork within a day or two?

 

If you or anybody comes up with a solution, I'd like to follow. 

You are describing the same situations I had, then the diluted glue seepage issue mentioned obove, then the spotty coverage with some of the glue being too thin....or seeped through instead of staying on the bottom surface.

Laying sheet cork turned out to be a big mess that I gave up on.

But good luck.  I hope you come up with a solution.

[selector]

Assuming you have the appropriate adhesive, and that it is spread well, the only way to keep rolled cork from wanting to lift is to place a full-coverage slab of either drywall or ply over it, as close to full dimension as you can manage, and as close to the perimeter as possible, and then lay on full cans of paint, an anvil, a tool box, your missus...whatever you can lift and throw up there.  A cut sheet of 3/4" ply would probably suffice all by itself, but some weights here and there would really help.

As for drying time, I'd expect the glue to be absorbed largely into the wood and cork, but it would still take a couple of days to set up...at least.  The DAP product would take maybe 12-18 hours, depending on how well sealed the interior of the slab is from air penetration.

[rrebell]

Pruitt

 

 

peahrens

I used the (thinner) cork sheet for my yard and simply used Alex Plus latex caulk, same as for my usual (HO) 1/4" cork mainline roadbed.  I applied the caulk to the plywood in "S" curves, spread it with a putty knife, laid the cork and put books on it over night.  Very easy. 

I would think the thicker carpenter's yellow wood glue would be tougher to spread, more expensive, etc.

I highly doubt that water from scenery building would cause any significant issue.  It was no problem with my scenery adjacent to my main roadbed nor my thinner yard cork.

 

 

I use caulk for roadbed on foam. Didn't really think about using it for cork onto plywood. It would certainly address the concern of wetting the cork enough to cause the bond to fail, though.

 

 

 

rrebell

Yellow glue witll proubly be the best for this. You can buy really cheap disposable mini paint rollers for a couple bucks, comes with tray and handle, bought a few over the years for my landlording job.

 

 

I used a foam brush to spread the yellow glue on one sheet of cork. It was a pain because the glue is so thick (but it worked). Wouldn't the rollers have the same difficulty? And when I paint a room, a standard roller absorbs a lot of paint that you can't get back out. Don't the mini rollers do the same thing with the glue? I've never used one of those, though I do have a tray and a few of them my late wife had.

 

I'm thinking the putty knife might be a good option for spreading the yellow glue...

 

Foam is not a true brush, wasn't talking a foam roller either. Yes there is paint lost with a roller but not near as much as from regular brush painting. Also it is much faster so the intial viscosity lasts longer. Last it puts on a more even coat.

[tstage]

I don't want this to detract from Mark's thread but I have a related question that hopefully might be beneficial to someone.

I have a roll of thin cork sheeting (~1/16") that has an adhesive peel-off backing.  Has anyone used this type of cork sheeting before and how well did it hold/stay held to your foam/plywood?

Thanks,

Tom

[Track fiddler]

Hi Tom

I haven't done self adhesive cork before but throughout the years we put self adhesive tile down on foors.  I was always a bigger fan of one piece floors but if done correctly the individual tiles would hold up pretty well.

It was standard practice that you would always apply a bond enhancer self stick tile primer to the underlayment before application of the peal and stick tiles.  Henry sells this product at Home Depot.

I would think it's the same principal.  The floors that were done correctly using the primer would hold up well even with light spill water conditions in bathrooms and kitchens. 

We could always tell the probem floors we tore out where someone had skipped this step.

On an extruded foam application I would think one would just scuff up the surface with a fine abrasive and clean well with alcohol prior to application.  The primer application isn't necessary as foam is not porous like wood.

As far as the quality of adhesive on self stick cork, I am not real familiar with longevity ratings like the ones on floors.  The self stick cork manufacturer may have a data sheet on the internet.

 

 

TF

[JDawg]

I use construction adhesive for laying all cork. Why you ask? Allow me to tell you in the following rant. 

 

I always have lots of half tubes of GP construction adhesive and subfloor adhesive left over from various jobs (I'm a general contractor). So I said to myself: "Self, if this stuff can hold down a construction site, why not cork to plywood." Self to Self: "well good golly gosh! I think I need to sit down. All this deep thinking gave me a headache!"

In all seriousness though, i use construction adhesive/subfloor adhesive for all my cork laying. Benefits include: super strong adhesion, never needing to tack cork strip curves (seriously, it's instant grab), water clean up, no worrying about bubbles in cork sheet, just smack it down and apply pressere with hands ONCE, no weights needed.

 

I have done this for several layouts of mine and several of my friends layouts. Results guaranteed! No, really, this works super well. Never had a single problem. Well, I take that back. If you ever have to pull the cork up, it won't. Period. Trust me. So that super adhesion is a bit of a doubled edge sword. Overall though, 10/10.

[Doughless]

selector

Assuming you have the appropriate adhesive, and that it is spread well, the only way to keep rolled cork from wanting to lift is to place a full-coverage slab of either drywall or ply over it, as close to full dimension as you can manage, and as close to the perimeter as possible, and then lay on full cans of paint, an anvil, a tool box, your missus...whatever you can lift and throw up there.  A cut sheet of 3/4" ply would probably suffice all by itself, but some weights here and there would really help.

Yep, rolled cork wants to lift.  And if you use wood as the weight and the glue is thinned too much, it will seep through the cork and glue the plywood to the cork.  Then lifting it up becomes a huge mess and a failed project.  Personal experience.

Someone suggested wax paper as an intervening barrier.  That should work.

Getting a large enough flat weighting surface that isn't made of wood could be a challenge.  I didn't happen to have any spare steel plates stored in the basement, LOL.

[Track fiddler]

I like to use Alex Plus caulk on any sub-roadbed yard or track applications.  It holds quite sufficiently for modeling longevity but is forgiving unlike permanent adhesives.  Just in case you ever want to make changes in the future.  The products easy release makes those changes simple.

 

 

TF

[dknelson]

Pruitt

The second sheet curled upwards, and even though I weighted it too across the entire surface, the long edges where the cork was curling up didn't adhere well. It's not a big issue, but it's bothersome. So other than laying the cork out flat and weighting it for a week or two to mostly get it to relax, what practical methods are there to relax the cork within a day or two?

Two words: "Strategic tacking."   Assuming good adhesive the tacks or nails can be removed later

One thing about sheet cork, which I sometimes use for yards, is that it "inherits" any little variation in the surface below it, whether that is plywood, homasote, or as has been mentioned above, irregularly applied adhesive.  Prep the area first with some sanding.  And once the cork has been glued onto the base surface, use a hard roller such as wallpaper needs and really press down.  And then the cork itself will benefit from some sanding afterwards.  

Dave Nelson

 

 

[richhotrain]

tstage

I don't want this to detract from Mark's thread but I have a related question that hopefully might be beneficial to someone.

I have a roll of thin cork sheeting (~1/16") that has an adhesive peel-off backing.  Has anyone used this type of cork sheeting before and how well did it hold/stay held to your foam/plywood?

Tom, I have a package of thin cork sheeting, and it is 1/16" thick. I bought it to use as strips of cork to step down from the mainline to the yard. I used Woodland Scenics Scenic Glue to bond the strips of cork to each other and to the plywood subroadbed. It holds just fine.

Rich

[ndbprr]

I guess I will always be a curmudgeon but cork has been around at least since the 1940s.  Eventually it will dry out harden and create dust and more noise. I would experiment with vinyl flooring underlayment. Comes in a roll. Lays down nicely.  Doesn't age and keeps noise down.  Just my two cents

[rrebell]

ndbprr

I guess I will always be a curmudgeon but cork has been around at least since the 1940s.  Eventually it will dry out harden and create dust and more noise. I would experiment with vinyl flooring underlayment. Comes in a roll. Lays down nicely.  Doesn't age and keeps noise down.  Just my two cents

 

True but not true, there have been many grades of cork used over the years, in the early years I beleive they used bottle cork, very different from the stuff we use which is made up of the outer shell of the cork tree where bottle cork come from the inside of the bark. The nature of the outside bark is what gives our current cork its durability and there is a real difference between brands. I use Midwest but avoid some that more black in it as about 20 years ago they experimented with putting more impuritys into the roadbed due to a cork shortage, that stuff was almost impossible to sand.

[Doughless]

BTW, as a replacement for rolled cork that I could never lay correctly, I used a few packages of those 12x12 squares you can get from Walmart.

Pricier, and suitable for a smaller area, but the smaller size and uniformity allowed me to lay them like tiles and achieve the same results.

The stuff I used only came in 1/4 inch thickness, and the cork was softer if that matters.

Maybe there is a product that comes in thinner dimension yet uniform pieces that would be easier to lay?

[Pruitt]

Thanks for all the suggestion and ideas, everyone!

Just to close this out, I laid all the cork using full strength yellow glue, spreading it with a putty knife for tha main blulk and a foam brush to cover the edges. I weighted each section down as I applied it.

Here's one cork section just before installation, showing the yellow glue more-or-less evenly coating the surface. 

Here's the completed sheeting in place (except for the far end, where I still need to work out the curve away from Thermopolis), with track sections laid roughly in place to see what track I need. I also still have two turnouts to build.

Thanks again for all the ideas! They were all helpful; even the ones I didn't use.

[Medina1128]

I would apply white glue or caulk. Apply in a back and forth pattern. Set your cork down, then roll over it with a wallpaper roller. This will spread it evenly under the cork.

[FowlmereRR]

I have had good success using double-sided tape - the heavy grade stuff used (here in UK at least) for sticking down carpet tiles to chipboard floors. I ensured my plywood (good quality birch) was clean and smooth first, then applied tape with one side still protected with its waxy backing paper, all over the surface I wanted to cover. Then used a roller to bed it down.

I then laid my cork sheet over the area to get the alignment right, held one end in place with something heavy, then gradually worked off the backing paper from the tape, pressing the cork in place as the sticky bits were exposed.

Once down, another good workout with the roller. It has been down for over a year with no problems and, when I recently needed to do some track mods, it was easy to cut through cork and tape and peel off the unwanted bits with a scraper, leaving a blemish-free surface.

As an aside - I have stuck down my Peco flex track to the cork with wood glue (here in UK sold as Evo Stik in big blue bottles). Again, no problems, but could get track and switches off undamaged when I needed to.

Happy bunny!

Bob