In a thread a couple weeks ago we discussed GLUING plastic.

Specifically HDPE and HMW plastics. Today I had to go to Dallas on business and I stopped by the plastics company that gave me my starter pieces. Today they gave me a 3/4" piece 6" x 72" and a 3/8" piece about the same dimensions. This kind of piece at Rocker is high dollar; I suitably thanx the young man.
Now to the thrust of this report; according to the plastics man there is no way at present to glue two pieces together or to wood or to metal. To connect them we will have to mechanically join them. He suggested drill, counter drill, tap the base piece and screw it together. Another suggerstion from them was to mock up the assembly with wood and work out the dimenisions; then work plastic. This is what I think I will do. But; first I will learn to take pix and to put them on line so I can benefit from from your help.

Ray Gerdes in beautiful Texas
 
That is surprising. I know Plexus can glue plastics and I have used it successfully on snowmobiles when I smacked those stupid things beside the trails that seldom move...most people call them trees.

You can also weld plastics very easily. Get your heat in the 500º range, apply some filler rod and add 5-6 pounds of pressure and you will get very good adhesion. I've made plastic tanks this way for boats that passed hydraulic testing.

Here is a tip though...for filler wire...try to cut some plastic off the part you are trying to weld if you can. It is hard to tell different plastics apart. For instance when I weld up snowmobile skis (they are plastic now) I shave filler wire off a spot that is not noticeable to make sure the weld will be of the same plastic the ski is made out of.
 
Travis - I know you are right because the gas co just welded the leaking pipe under the street in front of our house. Orange plastic and a special heating cone. And yes; years ago in crafts my kids glued plexiglass with a liquid like CA. At the plastics place we were only talking about these high density plastics they gave me. I will pursue this again when I get the chance. They did say the sign makers use materials that are glued. I do know from the farm; PVC is easy to glue, ABS not so easy, and the flexible black pipe we laid in 100 & 500 foot coils did not glue at all; they had to use special fitting and clamps.

I view many of your posts with interest because you display common sense and mechanical skils. My logging experience was limited to cutting cedar for square poles and fence posts and various hardwood for lumber. I have built several barns and sheds with home made lumber. We used to cut firewood, but I got too old for that. I envy your welding skills; I am a muddauber with my Miller Bobcat. If you don't have muddaubers up there, they are wasps that put mud "nests" everwhere.

Ray Gerdes in beautiful Texas
 
I have a friend of mine that has a machine shop and he machines this stuff all the time and has for years he has yet to find anything that will stick to that stuff but thats why you use it because nothing will. Save your energy as it does not exists as of yet.
Jay
 
I have tried using Delrin for several projects intended for sale. After the fact, I learned from trying and from supplier that the stuff won't glue, no way, no how. There are a lot of 'plastics'. Some will glue OK. Some will glue with special glues, e.g. PVC. And, some, like Delrin won't glue at all.
I have tried finding glues for UHMW and UHD polys and have not found anything. Won't say it can't be done because I haven't checked with the experts. One supplier told me there is a special glue for them but he doesn't know what it is.
 
Have you guys heard of, and or tried Plexus? Its not your normal adhesive.

I had never heard of it either, but the stuff is designed for plastics and has amazing strength. When they first started using it on boats, I had some major problems with it because sail boats often come in with caribiners and other metal rigging parts, bent twisted and ripped apart from the wind. Surely sticking a piece of steel against fiberglass with some glue (plexus) would result in carnage. Nope shackles get broken before this stuff lets go...tough stuff.

There are several kinds of Plexus, but the kind designed for plastic is obviously what the original poster is after. Of course you can weld any plastics. It is after all a fusion on a molecular scale. Heat simply expands the molecules, then pressure of 5 pounds or more forces them together, and then it "locks" as it is cooled.

As for Delrin...I've worked with this a lot. Its hard to get a finish on, but here is one property that few people know about...when it gets wet, it actually swells a bit like wood, so when working with it (on bow rollers in my case) you have to turn it down smaller then what the print says so that when it gets wet, it will swell and still work.
 
heres your answer

You are correct. Plexus will not bond any of the mentioned poly olefin s
without some sort of treatment such as flame.

However, I can recommend you consider a 3M product DP8010. I have used it
and it works well. It takes a long while to cure, but it is very effective.

When in doubt,, ask.
 
Travis, there are some kinds of plastics that cannot be welded. It's been awhile since I was in the industry, but I think that thermoset plastics cannot be welded. Examples that cannot be welded are epoxies and unsaturated polyesters. These form long polymer bonds with a chemical reaction when they cure.
Thermoplastics are the types that can be welded.
 
Of course you can weld any plastics. It is after all a fusion on a molecular scale.

You know in hind sight...that was a pretty ridiculous statement to make. Plastic is generally a very broad term for a very wide array of products. Its kind of like calling something metal, so you are probably right Paul, the long polymer types of plastic cannot be welded. As I said, it was a pretty dumb statement to say.

My bad...my apologies! :)
 
Top