Bonding wood to styrene?

Padawan v 2.5 · Post by **Padawan v 2.5** » Fri Nov 10, 2006 10:02 pm

Title says it all folks. What glues or epoxies have you used to bond wood to styrene? I have a wooden structural frame that I intend to skin with sheet styrene, but am unsure how to attach it.

P@T

DennisH · Post by **DennisH** » Fri Nov 10, 2006 11:02 pm

Contact cement. Coat both surfaces, let them dry, stick 'em together and Bob's your uncle!

Dennis

Lt. Z0mBe · Post by **Lt. Z0mBe** » Fri Nov 10, 2006 11:21 pm

Pat,

This scratchbuild was built over a balsa skeleton. I had excellent results with good old Loctite super-glue gel.

Every piece of the model in contact with the balsa uses the Loctite CA gel and let me tell you, when trying to remove the .020-inch styrene from the wood, it would rip instead of come loose.

The .040 stuff would rip the balsa away rather than break the bond.

I hope this helps.

Kenny

Padawan v 2.5 · Post by **Padawan v 2.5** » Sat Nov 11, 2006 12:05 am

Indeed it does. Thanks Kenny.

P@T

Kylwell · Post by **Kylwell** » Sat Nov 11, 2006 12:14 am

Contact cement, Tight Bond, Gorilla Glue, Thick CA (you need to be quick with this one, soak the wood with accelerator and put the CA on the plastic).

If in doubt, bolt it on.

Padawan v 2.5 · Post by **Padawan v 2.5** » Sat Nov 11, 2006 12:20 am

Kylwell wrote:If in doubt, bolt it on.

People keep telling me that this week, what's going on?

P@T

Kylwell · Post by **Kylwell** » Sat Nov 11, 2006 12:25 am

They think you're nuts?

For your bolts that is.

Mark Yungblut · Post by **Mark Yungblut** » Sat Nov 11, 2006 3:05 am

I would say contact cement if you are not concerned with the longevity of the model. The problem with most contact cements is that they can be affected by heat, humidity, etc. If you use a "hardcore" contact cements like those used in the flooring industry are not likely to be effected the same way but are seriously more caustic, there fore likely to melt your styrene sheet.

What I would do is create a stable base to glue the styrene to the wood. What I have done in the past is to put a skim coat of 2 ton epoxy on the wood and let it harden (I use the 2 ton because it is a stronger adhesive than 5 min. and the working time is about 20 to 30 min. This will give you plenty of time to spread it out evenly with a palette knife). Then rough up the face of the styrene that will be in contact with the "skimmed" wood. A pass with 60 or 80 grit will give you a great "tooth" for the 2 ton epoxy.

Then skim coat both surfaces and let them set up for 20 min. put the styrene in place and tape/ clamp/pin it in place. An hour later you should be good to go and have a stable base to detail as you see fit.

Hope this helps.

Mark

Chacal · Post by **Chacal** » Sat Nov 11, 2006 6:38 am

If you're skinning styrene over a wood shape, remember that if the styrene is to be formed over the wood (say a wooden cylinder with styrene sheet wrapped around it â€“ your basic "hull" deal), the ends of the sheet will try to come loose. You might bolt them on

or just glue a strip to cover the gap.

I would second Mark's suggestion (I like working with epoxy), but if your wood is balsa, it may be too porous and weak to stay put â€“ the wood might come apart instead of the glue. In that case I'd suggest you prime the balsa (or any open-grained) wood with resin. Mix a small batch and "paint" it on with a disposable brush. The more porous your wood is, the better it will suck the resin up, and that's good, because the more porous the wood is, the more it needs resin reinforcement. After the resin cures, sand it and the surface should be excellent for gluing.

[edit]I forgot to mention that epoxy adhesives are usually too viscous to penetrate deep into the pores of balsa wood, so they make a surface layer of epoxy (half to one milimeter), while resin penetrates waaay deeper (in some cases up to four milimeters), making a composite â€“ cellulose fiber reinforced resin â€“ so to speak, which is much harder to pull apart.

DX-SFX · Post by **DX-SFX** » Sat Nov 11, 2006 1:37 pm

If you're skinning styrene over a wood shape, remember that if the styrene is to be formed over the wood (say a wooden cylinder with styrene sheet wrapped around it â€“ your basic "hull" deal), the ends of the sheet will try to come loose. You might bolt them on or just glue a strip to cover the gap.

..... or bind the styrene around your wooden core with tape and dip it in boiling water for a few seconds. It'll hold the same shape once the tape is removed and won't need any mechanical fastening other than the glue.

Epoxy is good but slow. Thick superglue is probably the best. Contact adhesive like Evo-Stik has a strong solvent in it which may melt and distort areas of the styrene particularly if it's thin sheet. If you're sticking it to a frame i.e. at edges only, which your question suggests, just go with superglue.

Mark Yungblut · Post by **Mark Yungblut** » Sat Nov 11, 2006 2:58 pm

One thing I forgot to mention is that you will need to be aware of bubbles particularly if you use the contact cement. I wouldmake sure to gat a narrow roller and lay the sheet down starting at one end and rolling out the extra air as you go. If you get a buble you are likely to have a heck of a time getting it to lay down.

big-dog · Post by **big-dog** » Mon Nov 13, 2006 4:24 am

I tried gluing 2 pieces of styrene with polyurethane glue (gorilla glue) just for fun, and it didn't work. The foaming seemed to hold the pieces together, but they broke apart at the first touch.

DX-SFX · Post by **DX-SFX** » Mon Nov 13, 2006 4:46 am

You may find epoxy does the same thing if you don't roughen the plastic sheet first. You'll get a better bond with epoxy but it can still separate. This sounds counter intuitive but try balsa cement in a tube. You can stick ABS with balsa cement. Some of the old Graupner glider kits provided ABS fuselages and canopy frames which could be stuck with UHU Hart (balsa cement). The "S" of ABS is "S"tyrene so it's worth trying. I wouldn't use it for laminating sheets though because it's air drying. Plastic to Balsa would be fine because the cemernt solvent soaks into the wood. On an open frame with airspaces it wouldn't be a problem. I still think superglue offers the path of least resistence though.

Padawan v 2.5 · Post by **Padawan v 2.5** » Mon Nov 13, 2006 8:38 pm

Okay, contact cement worked not at all. I'm going to try the CA after sealing the wood.

P@T

DennisH · Post by **DennisH** » Mon Nov 13, 2006 8:46 pm

What dimensions are your wood pieces? Plywood on the flat, 3/4" ply on edge, 1/4" ply on edge..? Straight or curved surface? What's the thickness of the styrene?

Inquiring mind want to know 8) .

Dennis

Padawan v 2.5 · Post by **Padawan v 2.5** » Mon Nov 13, 2006 10:12 pm

I am attempting to glue a .040 inch thick piece of styrene to a wooden frame on surfaces about 1 inch across by 39 inches long. I have applied a thin layer of wood glue to seal the wood. After it dries I will scuff it with sand paper and try to glue the styrene down with CA.

P@T

DX-SFX · Post by **DX-SFX** » Tue Nov 14, 2006 5:39 am

You don't need to seal the wood with PVA. You'd be better spreading thin superglue over the wood to seal it and then there's no bonding issues. You can smooth the wood with fine abrasive paper after the superglue has soaked in and set which you won't be able to do with PVA on it. Then you can glue your plastic sheet down with more superglue.

rocketrider · Post by **rocketrider** » Tue Nov 14, 2006 11:40 am

You can try some stuff called Liquid Nails I have used it to bond wood to steel & plastic to carpet, and it has held great. (dries quickly though).

I believe you can get this at a local hardware store, and costs around $3-$5 a tube.

Glen

Falcon5768 · Post by **Falcon5768** » Tue Nov 14, 2006 12:06 pm

All you need is good old superglue if its a small project. Thats all I used on the front half of my torp deck for my modified PL 1701.

I have also used epoxy for a pair of baghnakhs I made for a cosplay costume.

Padawan v 2.5 · Post by **Padawan v 2.5** » Wed Nov 15, 2006 8:37 pm

Okay, the contact cement not only didn't cement the plastic to the wood, it actualy warped the parts forcing me to make new ones. Grrrr.

P@T

Kylwell · Post by **Kylwell** » Wed Nov 15, 2006 8:40 pm

Are you roughing up the glue side of the plastic with some 80 grit?

Padawan v 2.5 · Post by **Padawan v 2.5** » Wed Nov 15, 2006 11:01 pm

No, I'm roughing it up with an aluminum bat and brass knuckles.

P@T

Mark Yungblut · Post by **Mark Yungblut** » Wed Nov 15, 2006 11:04 pm

P@T,

I think the 2 ton epoxy might be your best bet as you are not likely to get any warping of fthe styrene (provided the gaps in your frame work are not too big).

Just my 2 cents,

Mark

Kylwell · Post by **Kylwell** » Wed Nov 15, 2006 11:05 pm

That works also, just not so well as coarse grit.

Contact cement was, obviously, too hot.

Have you tried the epoxy yet?

DennisH · Post by **DennisH** » Thu Nov 16, 2006 12:12 am

Can you post a picture of what it is you're working on?

Embarrassingly enough, I can't seem to visualize what it is you're doing.

Dennis

Padawan v 2.5 · Post by **Padawan v 2.5** » Fri Nov 17, 2006 6:41 pm

CA worked just fine. Now I just need a few more bottles...

Whatever the question, crazy glue is the answer.

P@T

big-dog · Post by **big-dog** » Tue Nov 28, 2006 6:16 pm

To clarify my prior post, I did pre-sand the bits of plastic before trying the polyurethane glue, It just doesn't seem to stick to styrene.

I'm surprised the contact cement failed. I used LePage's 'Green' non-toxic contact cement on a foam USS Voyager to glue thin styrene sheet accent panels, they're still on after 3 or 4 years.

jack wendt · Post by **jack wendt** » Sat Dec 02, 2006 12:31 pm

okay, i know you are not going to like this answer and think it would be too difficult, ....

but vacuforming will guarantee that it will be snug as a bug in the rug. keep your shapes simple. then glue on your doo dads on to the plastic to finish out the model. you can leave the wood in the vacuform, or remove. you can fill the vacuform with resin or plaster of paris, or leave open.

vacuforming is a lot easier than some would have you believe.

a 4'x8' sheet of styrene plastic would be less than $20. if you use .020 plastic sheet, then the thickness of the sheet will be reduced to about half of that or around .012, once it is vacuformed ovver your blank/part.