Cut some MDF up tonight, cough cough. Dust collection is now on my christmas wish-list.
Anyway, I’ve gotta glue some tempered hardboard to MDF for a sort of utilitarian desk I’m making for wifey. Any advice on what sort of glue? Off the top of my head, I was figuring on Gorilla glue or the Elmer’s equivalent, but the instructions for those generally say it’s got to be over 40 degrees to use the stuff and my garage isn’t heated. Thoughts? Ideas?
did
Blah, yada, whatever, Hi how are you today
Framing the floor inside a crawlspace foundation keeps a gable-end addition close to grade.
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Replies
Put a portable garage heater on that wish list as well. Stay away from the kero heaters or even the propane as to fumes. I don't know of any glue that does well in the cold.
Little workshop attached to the garage has a wonderful cast-iron stove, and not enough room to do the glueup. Phooey. Maybe I can heat the bits with an electric fan heater first.
didBlah, yada, whatever, Hi how are you today
I use the type II glue with the MDF screws and the step drill from McFeely and rabbits and dado's when ever possible. The gorrilla glue needs moisture to react so if you use it dampen your glue up parts.
Cold Cure epoxy with Jet cure hardener will go off below zero and quick.It is an expensive option.Otherwise how about solvent based contact adhesive and a fan heater.You wouldn't have to heat for long
Use a mechanical fastener for peace of mind, is my thinking--and the glue.
A couple of clamp on refletor lamps with some PAR-75s not omly bring much needed light, but, they will also warm a space up for you--and probably enough to set the glue.
Did -
I've been aprehensive, although thus far successful using Tite-Bond II the yellow PVA stuff) in my less-than-the-required 50 degree temps. I have an old electric blanket I lay out over the cabinet face frames for an hour or so before glue-up time to bring them up to a decent temperature, put the glue bottle in the microwave for a half minute to take the chill off it just before assembly time, and so far .... so good. I keep the blanket on the workpiece overnight as well on low temperature just to be sure.
I'm in agreement with the suggestion of using mechanical fasteners as well as the glue. I've been biscuiting the frames to the cabinet just to make sure.
Dennis in Bellevue WA
[email protected]
Careful with any glue containing water. Laminating a top, the glue line will swell slightly, then shrink as the water goes away. It will cup the top. I'd use a contact cement to laminate the top. Otherwise, glue hardboard to both sides. Solvent types work in colder temperatures, but I'd still do a little tent and warm things up a bit. My shop is cold, but I always heat it up for a day with portable heaters before doing any glue-up. I've not found any normal sort of glue that works real well when its below about 50 or 60. Just hang a sheet of plastic and heat the 10 square feet that needs to be warm.
I will have equal-thickness hardboard on both sides of the MDF, so assuming I get the whole sandwich laid up at roughly the same time I shouldn't have warpage issues. I am planning to do mechanical fasteners as well, though not the confirmats as those are too long.
I've never used contact cement, and I don't really want to start now. Epoxy would be too expensive and hard on my router bits (I'm pretty experienced with West System), so I think the choice is between the Titebond II and polyurethane glue.
Unfortunately it's gotten colder (I think the temp. dropped 10 degrees in the hour I spent in the garage last night), so I may have to pick the right day. I suppose I could make the layup, clamp with screws, and then move the whole thing into the heated shop to cure.
Lots of time to think about it, still.
didBlah, yada, whatever, Hi how are you today
One thing I forgot to mention with respect to ploly glues - they expand quite a bit. Using it for your project would require quite a few clamps and cauls and even pressure over the entire surface to avoid a wavy surface I think.
...........
Dennis in Bellevue WA
[email protected]
I would search long and hard for a vacuum press before doing this with clamps and cauls.
To do ONE? I ain't going into production here! I figure clamping will be done with screws and a whole lot of good ol' gravity (i.e. more MDF and particle board and old weight plates and firewood and buckets of sand and maybe even me for a little while).
didBlah, yada, whatever, Hi how are you today
Unc' is right, though about using a vacuum press for this large a veneer project. I wouldn't even have polyurethane glues in my vocabulary without one! If you've never used it before, you'll be (unpleasantly) amazed at the force with with the foaming action takes place.
You said you weren't thrilled with the idea of working with contact adhesive but I'd go that route if it were me. Try to get your hands on some old venetian blinds and take the slats out to use as separators to hold the hardboard in position after the adhesive has gotten to the point where you can bond it to the MDF. Work from the middle taking out one or two slats at a time to work the bond to the ends.
It's not as daunting as it seems and you'll have far less cleanup than with the poly glues.
As for using screws for the clamping mechanism - I'd suggest drilling pilot holes in the hardboard first since there's a better than even chance you'll get 'bridging' (think that's what it's called) where the screw wants to push the hardboard away from the substrate............
Dennis in Bellevue WA
[email protected]
If it was me, do it on your kitchen table! Then take the ol' gal out to dinner.Use white glue - that yellow stuff flashes off too fast. Contact cement will make you drunk - not good drunk. Neither of those materials is very porous so they won't absorb much. Cut your pieces slightly over size, lay the first piece of masonite down, pour out some glue, trowel out a thin layer with a scrap, lay down the MDF, more glue, second piece of masonite. Try to get one good long edge. Weight it down with whatever you have - I've used bricks, Tool boxes, milk crates full of nails and screws... leave it atleast overnight - better longer -12-16 hrs. Then trim it square. No clamps, no fasteners.
Oh, and you might want to use a couple drop cloths!
That's kind of my layup - what I'm actually doing is cutting the bottom layer (hardboard) to the exact size, then the mdf a bit bigger (like 1/8"), then the top hardboard a bit bigger yet. The bottom hardboard will be a template for a top-bearing pattern cutting router bit for the other two layers.
This top is pretty good sized - 48" deep, and almost 80" wide, to fit in a corner - see the pic of the CAD model of my wife's office area...
View Image
did
Blah, yada, whatever, Hi how are you today
Edited 12/11/2003 3:18:33 PM ET by diddidit
Did,
Just go but a can of stayput & be done with it ! Available at most cabinet supply shops. You should acclimatize ( 24 hrs at the same temperature ) all your materials in the warm room. RF
On a hill by the harbour
My first choice for something like this would be contact cement. I use it on a fairly regular basis and it has never ever let me down.
No cauls, no clamps, no vacuum press, no veneers expanding or swelling, just a few minutes with a roller to ensure good contact between the faces.
Downside is the temp. I do think contact cement needs the materials to be around 65 degrees for 48 hours...24 before fabrication and 24 after.
Get cement on both surfaces and allow to tack up as required. Set a series of dowels on your base that is cemented. Place the top over the dowels. Align. Algin well. Then one-by-one, slide the dowels out to allow the top to make contact with the base.
Roll it, then go have a beverage.
A cabinet shop in town even uses electric blankets. Semi high-tech ones, but a generic cheapie would work to keep the material warm.
I can't beleive it took so long for someone to come up with the only sensable sollution : the kitchen table.
Kitchen table isn't big enough. Kitchen floor isn't flat enough (scary but true). House floor has an overenergetic almost-three-year-old on it. It's got to be done in the garage.
didBlah, yada, whatever, Hi how are you today
In my experience, the moisture cure adhesives will eventually set up in cold weather. I think the issue is that there is too little moisture in the air to get the cure going at these temps, not that they will freeze.
That said, I think a contact adhesive might be better for this sort of 'large sandwich' application. Most of these should work in cold weather, since the solvents are very volatile.
I do not think the gorrilla glue is the best choice for this sort of lamination due to the 'foam out' factor.
Anyways, more directly to your temperature problem;
If you have a Halogen workshop light, these things generate a large quantity of radiant heat. Directed at the glue-up materials, these can both speed up the cure, and prevent freezing, even if the ambient air temperature is below freezing.
This method can also be used to prevent mortar from freezing, or accelerate the cure of any Portland material. Also speeds up epoxy...
They do make those electric radiant 'bulb-type' heaters, but the halogen lights are cheap, have adjustable stands, and serve a dual purpose....
Best of luck.
We used gorilla glue recently and it was outside on a porch, i.e. COLD! Seemed to work amazingly well.
Not to highjack this thread or anything but I was wondering...Gluing my subfloor down with PL Premium on the additions I'm doing here under the Advantech.
Also says not to use below 45 deg or something like that.
So does that mean I cant use glue for the last dozen remaining boards?
I'm gonna anyway.
Be stuck
andy
My life is my practice!
http://CLIFFORDRENOVATIONS.COM
Andy, should you even be using PL Premium for a subfloor? I thought the difference between PL Premium and PL 400 (sub-floor) was that PL 400 has some long-term flexibility in it that sub-floors need?
At least PL 400 works in the cold and can be applied to frozen lumber.
Looking at the Lepage website, I found these two questions/answers:
Which PL product is strongest?
Each individual PL Construction adhesive is designed to do a specific job and the strength factor is geared for that specific job. If you feel that your job is heavy-duty, then is recommended that you use a heavy-duty adhesive such as PL 400 or PL Premium. It is very important to understand the nature of the job at hand and to select the proper adhesive for that job. Read the label and if you are still not sure, please contact the LePage Technical Service Department.
Are all PL construction adhesives the same?
No, the PL Construction adhesives are all different. Each one is specially formulated and designed for a specific in use. Read all packaging carefully. Be well-glued,
Tim Ruttan
My lumber yard said it was what all the framers around here uses.
Thanks for the 400 idea for cold weather though.
I need to lay down another dozen boards next week.
Far as the PL Premmie goes...after it dries it has a seriously strong yet flexable feel to me.My life is my practice!
http://CLIFFORDRENOVATIONS.COM
I'd go contact cement.
Am i missing something here ?
Prob. need 2 coats on the MDF 'cause it will soak it up. 2 way better than 1 thick. thick wont dry and tack, just skin over.
Let ALL dust settle and don't make more for time being.
Roll glue instead of brush for nice even coat.
Don't plan to drive after. Good fumes. AND..... DON"T RUN A COMBUSTION-TYPE HEATER. BOOM !!!!!
also don't forget to lay plenty 'o dowels between and start to pull out and roll from center. Wifey don't like formica ? more pretty than hardboard.
Wifey gets what I make!
Actually, I don't think 3/4" MDF, even with HPL on the faces, is strong enough to handle that span without sagging, particularly with any kind of load on it. I'll also be attaching a height-adjusting keyboard tray mechanism to the underside of this thing, using oversized pilot holes filled with epoxy. I'd like a bit more beef for attaching, plus I like the dark/light/dark that the edges will show.
didBlah, yada, whatever, Hi how are you today