Laminating Extira?

[billp]

I am about to take on a job where I will have to laminate multiple sheets of Extira into 3"thick slabs which will then be cut as "slices" . These slices will then be machined as segments of a file which will be either 9"or 12"tall, and roughly 36 square feet in area.
Since I am a one person shop I will probably opt to use the .5" thickness so I can actually move the sheets around by myself. I'm afraid that .75" and upwards will be a bear. Also since this is going to be VERY heavy in the 3" thick form I willl probably build it right on my table, let the glue/glop dry and then machine the slices. In all I will have either 3 or 4 slices to do this way. As I do the cuts I can knock off surrounding areas of material, and possibly even hollow out some layers to lighten the final piece a bit..
What do I use that will hold Extira quickly and securely? This will be an indoor application so I am not worried about archival assembly materials either. Liquid nails?, Silicone?, Carpenter's glue? Has anybody even tried this yet?

[Brady Watson]

Bill,
This PDF (http://www.craftmasterdoordesigns.com/pdf/extpkg1104.pdf) FAQ recommends using polyurethane adhesive to fasten Extira. Above that, where it lists "Laminating" it just tells you to contact your local glue supplier...You'd think they would specify it themselves.

-Brady

[stickman]

Bill,

When we laminate up 3/4" Timblend (particleboard), we use a spray contact adhesive. WilsonART, is the manufacturer of the adhesive, its something that that comes in 16 oz spray cans. You spray it on both sheets, let them dry, five to ten minutes. It might be a little hard to do one personed. You might be able to use the stick method to lay up the sheets. You would be able to glue and machine within minutes of sticking the two sheets. What are you looking to create? Interior or exterior application?

Just my late evening... exhausted thoughts... Speaking of exhausted, anyone cut sheetrock with a shopbot? Yes I said SHEETROCK?

[beacon14]

Bill,

Mind if I ask why Extira if it is for an interior use?

I would be wary of contact cement as it will leave a thick, elastic glue line which could cause telegraphing depending on your finish. Polyurethane would probably work well if you can get reasonably uniform pressure across the assembly during the cure. That may entail a few extra sheets piled on top, and/or walking around on the stack to spread the glue evenly. What about epoxy?

Just the thought of cutting sheetrock with a router gives me the willies. I suppose with a 1/8" rotozip bit it wouldn't be any worse than cutting openings by hand with a rotozip tool, but that's pretty messy too. I wouldn't attempt it unless you have VERY good dust collection - the drywall dust will grind your bearings, rollers, pinions, etc. and be a real bear to clean up.

[Mayo]

How did you plan to slice the 3" thick lamination once it is dry? Or were you going to slice it to size first on a table saw or panel saw, then glue up until you got your 3" thick?

Do you have any 3" long cutting bits?

If you need to wind up with 3" thick pieces or letters that are basically 2D, you could just cut 6 of each (using 1/2" material), put some small drill holes for alignment in each part (do that first with the Bot before cutting out the shapes) and then glue up each, using dowel rods in the drilled holes to keep everything in position.

If you need raised shapes or letters on a background, you could cut those shapes from your 1/2" material, and glue or screw them to a background which you can build like an upside down pan, using a side wall height that would make it appear 3" thick.

[Brady Watson]

Doesn't seem like there is ANY info on the web from people who have laminated Extira 1st hand. Contact cement is probably going to be a no-go. Epoxy would take multiple coats...I'm thinking that something polyurethane would do the trick, and something thin enough to spread with a brush or roller...this rules out PU construction adhesive. It skins too quickly. Gorilla or similar might be the way to go. I imagine that you want a paintable glueline?

Mayo,
I believe that in Bill's post, he is calling the 3" thick laminations 'slices'...and he will have 3 or 4 of these 3" slices (18-24 .5" pieces of Extira TOTAL) for the entire job, if I understood his post correctly.

-Brady

[bryan]

Bill, I'd try the new Titebond III Wood Glue
It waterproof, I've used it to laminater other woood sheeting products together, great strength
Spread easy, Only problem maybe the dry time of 4 hours.

Bryan

[mikejohn]

Can anyone help an ignorant Limey.
Is Extira a high quality MDF?
If so, how easy is it to work?
Do you get a clean finish?
Is it sold in Europe, maybe with a different name?
Thanks
......Mike

[bleeth]

Bill:
I think it's time to get out the weldwood plastic resin glue bucket. I like to do my spreading with a fine notched blade after I pour on the estimated amount. You're not kidding this is going to be one heavy piece but at least with the resin glue your glue line is sandable and finishable and doesn't have nearly the flexibility of either contact cement or yellow glues. I use it with a vacuum press for all my furniture laminating including veneers and bending and have never had a failure. You might scuff the surfaces first as you go for a better bond. If you hate urea glue though then it's epoxy with cotten fiber (I'm an old West System cold molder myself), but then you have to be prepared for long term UV protection.
Dave

[billp]

I appreciate the ideas thrown out so far. Here is the nature of the job , so you'll see what we are dealing with;
The job is actually FOR the Extira company. They have an advertising agency who drew up a display for a trade show, and my part of the equation is carving the main focal point; a 6 foot long alligator cut out of Extira..it will then be mounted on a jungle pond photo backdrop for display..
Issues; we don't have the file yet, as it is presently being modelled from photos provided. Because of this we don't know the true size ( in terms of height of the overall 'gator..). I need that info so I can figure just how many laminations I will need to make up the total height.
Due to the weight of the material 1 inch thick sheets will be really tough for me to sling around my shop, so I am going to try and get .5" sheets from them. My "main slices" can be up to 3"thick as I DO have 3"long ball nosed bits for 3D cutting. BUT The composite piece will now be anywhere from 3-6 slabs of the material and should be pretty beefy after laid up. My thoughts originally were to machine the slices, "hog out" a good deal of the internal areas (while leaving a main block in the center for attachment purposes..), and then trim off the exterior Extira...Slide that slice off onto a rolling table, and build the next one..
SO a good,fast drying glue is needed to not only hold these pieces in place, but to give flat slices which can then be stacked on top of each other to achieve the final height. To add to the fun here, the last memo had the 'Gator being left unpainted so they can see the entire shape in Extira ( as well as every glue line I generate.......), as contrast against the jungle backdrop...This also means my slices will have to be pretty close as well.
Best news in all of this is that to my understanding the piece will only be used for this show, so it's not a case of having to make this ready for a national tour...

[elcruisr]

Bill,
have you ever worked with Protac? We use a fair amount of it here in the shop. It's designed for nip roller and vacuum bag work. If you have a vacuum hold down on your table you could roll out the protac, stack your sheets, place a caul board on top, cover everything with plastc sheet, duct tape the edges and hit the vac switch. It only needs about 1/2 hour of vacuum and then maybe another 2 hours and it's machineable.

It's vinyl based, has a rapid tack and quick cure. Forms a thin dark glue line and is suitable for for just about every laminating task I've put it to. Spreads with a glue roller ( or brush in a pinch ) and cleans with water. You can get it from CP Adhesives, who happen to have an excellent tech dept.

Eric

[beacon14]

That sure explains the choice of material. I would not do something like this without a vaccuum or cold laminating press. The Tightbond 3 or Gorilla glue sound like your best options for nice, tight, clean joints, but you need the uniform pressure (not to mention sufficient pressure) that only a press can provide. Haven't used the Tightbond 3, but I know the polyurethane glues are messy to work with and will turn your skin black.

If you can't find someone in your area with a vaccuum press, they aren't that hard to make. The biggest cost is the pump. I finally made one a couple of years ago for a big veneer job and now I use it all the time. If space is a problem I can show you how to make a "portable" one - all you need is a sheet of MDF a little larger than your glue-up, and some roofing membrane, and of course a vaccuum pump.

For 3" slabs, 4 layers of 3/4" is usually the easist and most economical way to get there. One more suggestion: hire a temp for half a day to help you handle the sheets. I've had good luck with a local temp agency that specializes in construction and the trades; for under $50 I can get a decent person who will follow my instructions for 4 hours, including workers' comp and payroll taxes, with no paperwork other than wrinting the check. How much is your back worth?

David B.

[waynelocke]

Bill,
Are you trying to laminate full 4 X 8 sheets or are you going to rough cut them before laminating? The full sheets would be a problem because the glues with a thin and ridgid glue line require pressure all over and the construction type adhesives leave a large and inconsistent glue line. If you cut the extira into smaller pieces, you could have them clamped and drying while machining other pieces. By my reckoning you would need 24 laminated blocks. Why not just dedicate a day or two to laminating. The smaller pieces would at least be manageable and you could better guarantee a good glue line.
Wayne Locke

[harold_weber]

Hey Bill,

Since the job is for Extira, why don't you ask them what glue they want you to use for laminating?

[Brady Watson]

Bill,
THIS (http://www.cmicompany.com/pdf/fa1104.pdf) is what you want.

-Brady

[bleeth]

Bill: Given the extra info I totally stick with the Urea based solution-easy to spread,sticks like heck, your choice (depending on vendor) of color from white to brown, sets in a few hours, and will certainly put up with temperature and handleing changes. Overall pretty inexpensive too!! When I'm stuck having to work with 1" MDF I have my supplier fork it on to a couple of sawhorses so I'm sliding it around my shop to start with. Keeping it flat and waist high makes handleing it a snap compared to a verticle rack.

Dave

[billp]

Thanks again for all of the latest suggestions. We are still in the dark as to the true nature of the job as the model has not been finished yet, so we don't really know the real depth of the final piece.
I suspect I will try to minimize the potential of internal body damage by cutting out as much material from around the pieces as I can, and that will also help minimize the pieces I am going to be handling.
I have just built two rolling tables specifically for this job and they both are at just about waist level. I am hoping to transition my moves from the van to the table to the 'Bot, etc. Then I can roll the table around as I get pieces to add to the project.
The gluing process may come down to how many hours are left when the files arrive. I am lobbying for the option to use long screws as well as adhesives to insure that each slice will hold together as well.
In the best of all worlds this will turn out to be 9"or less in depth, and I will use .75"materials to do the job. I promise to keep you all informed at how this goes...

[billp]

Latest update; I spoke with the folks from Extira at the Atlantic City Sign Show. They told me that they recommended the polyurethane glues ( Gorilla, etc.) for this kind of work. The trick seems to be be spreading it on as thin as possible so that when it does it's expansion routine it won't "lift" the sections. I will only be able to use fasteners in one of the three files I have to cut, as the two smaller pieces are sharply tapered at their tops, so I will try to use whatever I can (including the weight of the Extira itself..) to keep things together.
Good news is that I did get them to agree to a maximum height of 6", and so I will use the .75" pieces in stacks of 4 at a time. Just unloaded a dozen sheets of the stuff off of the delivery truck onto a table I made for this purpose. Of course 1200 pounds was a little TOO much for the table so we then had to move 8 sheets again...All this makes me appreciate Trupan even more...

[edcoleman]

Bill:

Try using a threaded rod for speading the glue over a large area. The threads act like a ridged trowel and keep the glue spread thin. I read that "tip" somewhere recently and although I haven't tried it myself yet, it sounds like it might be a good fit for this type of glue-up.

-Ed

[jay]

Bill, for weight, while you are waiting for the glue to dry, have you considered using the water fillable winter pool cover holders? Don't need a lot of water, can be quickly filled and emptied with the good old water hose.

[billp]

OK, the job is done! I learned a LOT about cutting /laminating Extira on this one...The capsule report is that Extira has most of the liabilities of MDF,Medex, etc. PLUS the added factors of being incredibly heavy, and it destroys tooling very quickly...! It also toasted my Porter Cable to the point I plan on finally getting a Milwaukee 3.5 HP as a replacement next week..
Gorilla glue worked VERY well for the laminations, and held up 100% during all the cutting. If you catch it while it's still a little "green" any oozing can be cut off with a razor knife..
Cutting Extira is a real bear..I used a 1" diameter,3"cutting length solid carbide bit for the roughing passes. Roughing passes were absolutely necessary since I was cutting 3"thick slabs of the stuff at a time ( see attached pix..). By the time I was done I had worn down the bit to the point it no longer had any edge to it's tip. using Artcam I was able to leave .2"of "surface" so that when I did the finishing passes(.5"ball nosed bit)I only had to go down that far. Of course this meant incalculable hours to do both passes, but it was the only way to cut through this stuff.
My normal technique is to leave a little "flange"around the slices so I can later fair multiple slices into a smooth transition. Better to have a little extra, than not enough...
The dust, ah the dust...Everywhere...! The ONLY positive thing I can say about Extira so far is that I do NOT seem to get those awful MDF sinus headaches when I'm in the same room as the 'Bot while it's cutting. Since I have a beard there are very few safety devices (short of using a hookah rig like Brownies third lung..) to keep from getting any dust in my lungs. In this case I stayed out of the room as much as I could while it was cutting.
I glued the full slices up again with Gorilla glue, and added a few finishing nails to hold things in place while it kicked. To make attaching the tail simpler I drilled indexing holes in both the tail and body and used .5"dowels.(They plan to assemble/disassemble this as they take it around the country..) I have NO idea how heavy this critter wound up being since I couldn't lift it up enough to get it on the scale... In fact I eventually had to glue the pieces up IN the crate and build it around him...
Realizing that things would be out of my hands once the air freight company picks him up ( yes they are going to fly him to Chicago...) I used 2 by 4" standoffs to keep the top from being used as a trampoline or base layer for anvils, lead keels, or whatever else people ship by air these days...
In short what I learned is that I don't want to ever work with this material again. The fact that it is rated for exterior use might be important to some people, but I'd rather carve my pieces out of foam or Trupan, and then coat them with Styrospray, or epoxy.
I think most of the following shots are self expalantory, if not let me know what needs more info...

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[alano]

Incredible work Bill. Absolutely Awesome!

[paco]

APPLAUSE!!! GREAT WORK BILL!!

I can imagine the dust!


Keep us informed of your testing of the Milwaukee performance...

[beacon14]

Bill

Spectacular!

If it were easy, anybody could have done it.

As for the dust, I recommend getting your hands on the biggest, baddest leaf blower you can find, open all the doors and windows (yes, I know it's cold out) and start at the end farthest from the door. You'd be amazed how fast you can clean your shop with a decent blower.

[bleeth]

Well Bill-That's a great lookin gator-In fact it reminds me of the one that tried to adopt my wife last time we went camping!!

Dave

[stickman]

Bill,

Nice work!! Did you happen to weight it?

Jay

[mikejohn]

Great work.
We don't have alligators in the UK, but I believe thats a male one.
Wouldn't a female have it's mouth open?

......Mike

[billp]

Jay,
By the time I had glued up the slices it was too heavy to hoist onto the scale,(and I doubt a standard bathroom scale could have handled it anyway...).I will guess it weighs between 350-400 pounds, plus another 150 pounds for the crate..
Mike for the same reason I was unable to turn "Al/Alice" over and do a chromosome test...
I did find that wearing proper safety equipment, such as this job specific helmet, was absolutely necessary to keep in the spirit of things as this project went along....
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