Laminating styrene: How long before carving on it?

[LDO]

I laminated 7 layers of Evergreen .125" using Testors liquid cement. It was in a vise for 24 hours. It's out of the vise now, but how long before I can do some serious carving/shaping?

[James Flowers]

I have done in less than an hour. I would think it should be dry in 24 hours.

[crazyjim]

I didn't knoe Testor's glue would hold Evergreen. I've alwaays used Tenax.

[LDO]

I have done in less than an hour. I would think it should be dry in 24 hours.

It's been almost 48 hours now. I think I need to let this cure for a bit longer. I had to brush a lot of it on so it would remain tacky while laying up 7 layers (plus a .040" template). It still has "boogers" that squished out between the layers. They're getting harder but still softer than the base plastic. I did a bit of sanding on the edge, but what I'm really concerned about is putting some serious taper on one end (Imagine a teardrop shape with longitudinal lines running through it). I don't want to have soft, gooey plastic in waves on this part.

Edited March 11, 2009 by LDO

[James Flowers]

Sounds like you used way to much glue. I only put a very thin coat between each layer. More glue does not make a better joint. It can make a part soft and ruin it. I put a very thin coat of glue on one part and then slide the parts together making sure the glue is spread between the parts even, by that time they are almost completely bonded. Sounds like you were trying to glue all the pieces together at once and used to much glue to keep them moving while trying to adjust the pieces to fit your form. Try gluing two pieces together at a time against your form when they fit, glue another to those and build it up slow. I only use Evergreen and have had no problems doing it that way.

[LDO]

Hmmm. I'll try that for the next one. Thank you.

[Art Anderson]

I laminated 7 layers of Evergreen .125" using Testors liquid cement. It was in a vise for 24 hours. It's out of the vise now, but how long before I can do some serious carving/shaping?

For starters, Testors Liquid Cement is perhaps the slowest-evaporating liquid plastic cement on the hobby market--I think it's little more than their tube glue, thinned out to a liquid consistency--so it is going to take time to dry completely. It may feel dry at the edges quickly, but once you carve into it, you expose still-soft joints, and the problem continues. This is based on experience--I did this same basic step, using early Squadron thick sheet styrene about 40 years ago, to laminate up shapes for carving into George Souders' 1927 Indy winning Duesenberg, and Tommy Milton's 1923 HCS Spl (Miller 122). It took weeks for the seams to quit shrinking after the body work was shaped.

A better alternative is to laminate these thick pieces of styrene sheet stock with CA glue, which does not shrink, does not depend on evaporation to set up or cure. Do this one seam at a time, press together tightly (clamping is NOT necessary, then go on to the next seam, repeat until you have the material thickness you need. Also, Tenax evaporates MUCH faster than the old-school Testors Liquid, and for a much less expensive alternative, see your local industrial plastics supply house/fabrication shop (where they sell and work with Acrylic -- Plexiglas) and get a large can of Weld-On #3, which is the same stuff as Tenax 7R, for a fraction of the price. But even this liquid will take time to dry out completely, but not nearly as long as the Testors stuff.

Art

[Harry P.]

You could also use a solid chunk of material, thick enough for what you want to carve out of it. No seams, no gluing, no waiting. You could use a chunk of basswood or a chunk of styrene. The basswood would be easier to carve and shape, but of course you'd have to seal it when your done shaping it, to fill in the grain. But that's easy enough to do.

[LDO]

Thanks for the advice, guys. Lots of knowledge and experience out there.

I'd love to try solid blocks of Renshape, but money is tight and I had the styrene on hand.