Glueing Styrene....

[mbshaw]

Last night while reading the Workshop portion in the latest issue of MR something hit me. Have I been using the wrong method of joining styrene? A gentleman wrote in inquiring about aging styrene. And in the answer to his question there was mention of glueing and welding styrene joints. I am currently scratch-building a bridge and I want to make sure it will last. I have been using off-the-shelf thin and thick CA from a local hobby shop. Should I be using something else?

[Anonymous]

There is glue specifically for styrene. Currently I use "Model Master Liquid Cement for Plastic Models" and Plastruct, plastic weld solvent cement. These weld the two UNPAINTED pieces together, BUT......................

AC is the glue to use if joining two PAINTED stryrene pieces together; the paint blocks the weld.

[Anonymous]

Try MEK or acetone to weld styrene sheet stock. I use an old drafting pen to dispense a very small amount to the seam. It will run and fill the joint, It dries in a few minutes and sets in about a half hour. I work on glass so that if some plastic runs out, I can remove the work and clean the glass with a razor blade. You can use squares and other metal tool to align the parts.
The Micro Scale glue bottles are refillable. They are good because they have only a small opening and thus, reduce the stink and danger as I work.

[jrbarney]

MB,
I'm not an industrial hygenist, but when a machinist and I built a 1/48th scale plastic model of the IBM helicopter hanger and landing pad in Owego, NY, we made sure we had PLENTY of ventilation because we had been advised that MEK is hazardous to humans. We used a hypodermic syringe to apply the MEK to the joints.
Bob

[wp8thsub]

Using CA isn't the way to assemble styrene. Solvent cements based on MEK are FAR superior.

Thicker and slower setting cements like Testors work well for a lot of styrene assembly. Much faster setting can be had from the likes of Tenax 7-R and Ambroid ProWeld. They bond almost instantly, very useful when attaching things like large structure walls, especially if the parts are at all warped. They work much faster than CA.

The problem with CA is that it adds thickness, which isn't desireable when trying to get parts to mate perfectly or when building rolling stock kits that have a lot of tight-clearance locating holes. Solvents literally dissolve the plastic parts into each other while CA adds a separate layer of glue.

[dknelson]

Many of the commerical glues/cements are MEK -- check the label.
It is dangerous chemical. I wonder how many users really follow the warnings and rules?
Dave Nelson

[mbshaw]

Thanks for the replies folks. Thankfully I have only partially built one plate girder out of 12. I'm heading to the hobby shop this afternoon to get some MEK.

Thanks again...

MS

[n2mopac]

I will concurr with my fellows above, use some sort of solvent styrene weld. CA is ideal for joining UNLIKE materials together (eg. styrene to metal or metal to wood). It makes a reasonably strong bond in such cases, but nothing will bond as well as fusing the peices to one another with a solvent.
Ron