Plastic and plastic welding

[sonoranjosh]

I have an outdoor kitchen that I use for all of my excursions. Despite my inability to cut a straight line, I somehow made it out of 3/4" plywood with a fold down front. It fits tightly in the back of my JK Unlimited. It has been punished across Arizona, Utah, and the Baja. When needed I pull it to the lip of the tailgate opening, fold down the cover, and everything I need is right there. The problem is the plywood is heavy! If anyone has input as to plastic welders and types of plastic, I'm considering rebuilding this beauty to make it lighter and better. Any thoughts would be appreciated.

Regards,

Josh Miller

 

[vtlogger]

okay... so its been 25+ years, but I used to work in a plastic shop and if I remember right they had a welder, or something similar in the tool room....to me it looked like the old wood burner's that we had as kid's, but yet different, I never used it but watched one guy ..it looked like he put the 2 pieces together and dragged the tip along the seam ( almost like fusion welding of some sort) ... I remember one of the guys saying that he like to work with delrin plastic, like I said it's been a long time but I hope it helps in some way and not confused you... good luck with it

 

[sonoranjosh]

Thanks vtlogger.........will have to look at it. Harbor Freight has the welder but I'm sure there are different types of plastic. Thanks much!

 

[AlbanyTom]

Pretty sure that for it's weight, most wood is a lot stronger than the kinds of plastic that you can weld. Lightweight plastic things are light because they are mostly hollow. Hollow is light and strong, like a hollow core door, or an airplane wing.

Good news is that you can probably make your own. One way would be to frame the outside of your panels in wood, fill the inside with pink builders foam, and wrap it with fiberglass, kevlar, or carbon fiber. Search for building model airplane wings, or kit airplane wings, for ideas.

Another options is aluminum. Aluminum is way stronger than regular plastic for it's weight, and generally better than wood, too. Lots of people build portable boxes and gun cases out of aluminum, it's easy to cut and work with. Think rivets, not welding - just as strong for sheet metal, and a billion times easier. 747 wings are riveted for a reason.

Post pics when you finish!

 

[MagicMtnDan]

Solvent bonding is yet another way to work with plastics. Acrylic, ABS, polycarbonate are but 3 materials you can solvent bond.

I hope you're post up pics of your 3/4" plywood box construction. I'm going to build my own custom drawer unit plus using 3/4" plywood. I can't imagine how heavy your unit is - did you go floor to ceiling?

 

[AlbanyTom]

All three of those plastics do solvent weld, and you could make a beautiful cabinet out of them. From my memory, abs and polycarbonate have very good impact strength, and maybe some have good tensile, but pretty sure all three have lousy elastic modulus. Or in other words, they're not very resistant to flexing. And they're subject to creep, which is slowly giving way when subject to long term load. But plywood will do that, too, when bending across the laminations.

I'm just reading the 3/4" thing. That's really heavy. Betting you're doing that because thinner plywood shelves would sag. Plywood makes lousy shelves, in my opinion. One of the features of plywood is that it bends easily. Great thing if you're covering a teardrop trailer. Bad thing for a shelf. It would be more work, but if you framed the shelves out of solid wood you could use much thinner shelves and save a lot of weight. Like 1"x1" oak frame with a 1/4" plywood top. For a 12" deep shelf, that would be about 1/2 the weight of 3/4" ply. (I'm pulling these numbers out of the air..you'd have to do some math or make some tests to see if they were strong enough.)

Or you could even make a wood lamination. Like 3/4" of balsa sandwiched in between sheets of 1/8" light ply. Would be expensive, but strong and light. Might even work with styrofoam in the middle.

 

[Silver dude]

There are plenty of people plastic welding on YouTube with the Harbor Freight plastic welder if you want reviews or ideas of how it works. I to would recommend the solvent welding. I've had good success with ABS in the past in model making. The solvent basically melts the plastic pieces together. With some ABS sheets and some basic ABS pipe glue from the hardware store you should be able to get places. The final result may not look amazing but it will be super durable and practical.

 

[thairish]

BONDIC | LIQUID PLASTIC WELDER
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[ripperj]

I also don't think plastic is your answer. I would make a frame from 3/4" stock and cover with 1/4" ply. The if it needs to be rigid,(like a table top) then 3/4" foam sandwiched between two pc of 1/4" ply is pretty strong.

Sent from my Passport using Tapatalk 2

 

[mudbutt]

... I remember one of the guys saying that he like to work with delrin plastic...

Delrin is not only very expensive, it is also toxic above it's melting point.

 

[Rattler]

I used to do auto upholstery and my old boss had one he used to repair trim parts that were A. hard to replace or B. for cheap bastards. It worked pretty good from what I remember but it was on softer plastics.

That guy that liked to work with delrin mentioned reminds me of an old co-worker who liked to clean the paint gun above a bucket of MEK. I couldn't stand being within 5 feet of it.

 

[SoCal Tom]

If you already have the 3/4 ply version, what about buying a good hole saw and reducing the weight. It might be a good compromise. I highly doubt that you need it to be that strong everywhere.
Tom

 

[GHI]

I'm just now learning about plastic out of necessity because I ran over a piece of metal that punctured my grey water holding tank that is mounted under my vehicle. I bought some plasti-mend hoping my holding tank is ABS plastic. Apparently, ABS is easily repairable. I've found you can basically make whatever shape you want with this stuff and some ABS sheets if you are somewhat creative.