Introduction to Plastic Tech

[Seanz0rz]

sean: what are you using for the cupholder itself? I need to make one for the Benz. I dont want to just cut out holes. I want soemthing to contain the liquid.

my actual cup holders will be a piece of pipe with a cut to fit cap made of sheet (not a glue on cap)

im still trying to find pipe with an inside diameter of 2.75" or there abouts, i havent had time to go to the hardware store. i will let you know what i find. if you need some help with your benz console, let me know, ive managed to learn alot over the last few years about console design...

[DHC6twinotter]

well that depends on the dimensions of the box and its intended use. small boxes id recommend abs or acrylic. larger i would recommend HDPE

Sweet! I'd like to eventually learn how to tig weld, so I figured maybe I'd build a box with drawers for the rear of the 4Runner. This thread got me thinking about using some plastic sheets for the sides.

[4runnerchevy]

I like this, thanks Sean. What about plastic glues that achieve a chemical bond. I use a Loctite product at work (I don't remember its name), but it does well with ABS, and other plastics. ?

I have some ducting for my Chevy motor, that has been worn through by a belt. I only use this ducting for smog, but I would like to fix it for real. I believe its ABS, should I weld a piece in or use the glue ?

[Seanz0rz]

The common glue for abs plastic is very similar to the sludge method, but it's dry time is in the single digit seconds. The sludge affords several minutes before it really starts to set andthe pieces can be repositioned. It is also great at filling gaps.

I'm interested in that locktite product. Please pass on the name when you can. It likely slightly dissolves the surface to achieve the bond. The good thing about sludge, it will be a solid piece of abs through the entire joint ( much like welding metal as opposed to epoxying it together.)

[surf4runner]

ive used a 2 part epoxy(locktite???) on ABS w/excellent results.

ABS also takes well to 'welding' (melting)plastic rods to repair it. can be sanded and filled before paint.
ive had this done to a MC fairing... more than once

[4runnerchevy]

We are out of the stuff at work. I am gonna use another Loctite Urethane Adhesive which seems to work really well on plastic radiators. Loctite U-05FL Hysol, 5 min, bonds anything, highly flexible, high shear strength. Its used in a small gun with a 1 time use mixing nozzle. For what I am doing silicone would probably work.

I'll still see if we have some empty bottle of the other product, the plastic stuff.

[mastacox]

acrylic - acrylic, often found in the glass section of home depot, is the most widely available in sheet form. commonly known as plexiglass and lexan. very useful plastic!

Acrylic is the common shortening of polymethyl methacrylate [PMMA] a.k.a. Plexiglass or Lucite. However, Lexan is completely different material, despite the fact that they are both "clear plastics."

Lexan (LEXAN) is a registered trademark for SABIC Innovative Plastics' (formerly General Electric Plastics) brand of highly durable polycarbonate resin thermoplastic intended to replace traditional glass and Plexiglas where the need for strength and impact resistance justifies its higher cost. It is a polycarbonate polymer produced by reacting Bisphenol A with carbonyl chloride, also known as phosgene.

I have made mechanical designs with Lexan due to the fact that it is easy to machine and does not flake or chip as easily as acrylics. Plexiglass is more difficult to work with, easier to scratch, and chips and flakes terribly when being machined. Additionally, Lexan is tougher, and is the material commonly used as bullet/explosion proof protection, such as in Mythbusters.

[Seanz0rz]

thank you for the clarification!!! i was thinking lucite when i wrote it, but put lexan by mistake and didnt even catch it.

[corax]

So Sean, what type of plastic does not go all Gooey with acetone in it? I love the info & think it could seriously help reform my p/u bushwacker flares to fit the 'runner, but every bottle I've ever put acetone into gets all deformed on me . . . you mentioned ketchup bottles? how are they marked?

[Seanz0rz]

any bottle with PP or PE on the bottom. walmart sells these really cool bottles, like the one pictured here:



i cant find it on their website, but its in the kitchen stuff with like the picnic stuff, its next to the red and yellow bottles for ketchup and mustard, has an item# 50232 and is made by Bradshaw International, if that helps. i guess normal people would use it for like a home made salad dressing or something. ive used my clean one to wash stuff out of my eyes a number of times!