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View Full Version : Make ABS Plastic Hoppers & Crash-Boxes?



Marshall/Ak
01-08-2013, 10:26 AM
I just noticed that there is a good selection of ABS plastic flat sheets on Ebay, for what seems like reasonable prices. ABS plastic is relatively easy to cut and glue, unlike the "Marlex" plastic commonly used on mining gear. It seems to be pretty tough and durable...if it cracks or breaks, just glue it. Do ya'll think a clone of Keene or Proline highbanker feed hoppers, or even the old-fashioned crashbox headers could be made from this stuff? All my homemade wooden sluices and highbankers only seem to last 2 yrs at most, before the wood is rotting and falling apart. (and they get water-logged and HEAVY!)

overtheedge
01-09-2013, 08:04 AM
I get my ABS sheets from CAC Plastics in Wasilla. Yep, easy to glue up. You can use ABS pipe cement or a cheaper solvent glue is MEK.

If you need to fill a crack or hole, mix some ABS cuttings with MEK and use as putty.

ABS is not real impact resistant, so hold back on hitting it with big rocks.
eric

peluk
01-10-2013, 02:14 PM
What is the material used in the Proline hoppers now? What is the best method for bending the ABS sheet? What is the material used in the older gasoline jugs(red)?

The question about the materials in the hopper and jugs has to do with resistance to sunlight.I have found the jugs will develop "webs" of cracks over time and they will rupture.Those large 285gallon white plastic tanks popping up here and there have a similar problem..The ones I'm referring to sometimes have a cage around them and they are almost a cube in shape.Maybe Marlex is more durable.A crashbox would take the worst beating.

Reno Chris
01-11-2013, 08:13 AM
Resistance to sunlight has a huge amount to do with pigments used in the plastic. Lighter and more transparent colors allow the sunlight to penetrate and damage the whole thickness of the plastic. Fully opaque pigments and dark colors don't allow the sunlight to penetrate. That's why the black plastic crashboxes very rarely show any sunlight cracking and damage, while the old style yellow floats, which allowed the sunlight to penetrate, almost always show cracking if they have been stored outdoors for much of their lives - even though I think both were formed from the same type of plastic (which was probably one of the forms of polyethylene).

overtheedge
01-11-2013, 12:10 PM
What is the material used in the Proline hoppers now?
I don't know.

What is the best method for bending the ABS sheet?
I use an electric heater. I have used my gas stove for small parts. Don't burn it. It sags when it is ready to bend.

What is the material used in the older gasoline jugs(red)?
Polyethylene. Rule of thumb, polyethylene is fairly flexible and polypropylene is rigid and breaks. Polystyrene is either expanded into Styrofoam or is the translucent jugs milk comes in. It is real susceptible to UV damage.

The question about the materials in the hopper and jugs has to do with resistance to sunlight.I have found the jugs will develop "webs" of cracks over time and they will rupture.Those large 285gallon white plastic tanks popping up here and there have a similar problem..The ones I'm referring to sometimes have a cage around them and they are almost a cube in shape.Maybe Marlex is more durable.A crashbox would take the worst beating.

These tanks are polystyrene. A friend of mine got a few from Mat-Maid and found that they needed to be kept covered or else they crazed and cracked.


Like Chris pointed out, the more pigment in the plastic, the greater the resistance to UV.

Poly plastics tend to be thermo-formable. But NOT ABS pipe. PVC pipe thermoforms easily.

There is a bunch of stuff on the web about thermoforming. Check out MAKE magazine and u-tube.

Dan from NY posted a bunch here awhile back on thermoforming.
eric

flintgreasewood
01-11-2013, 03:50 PM
PVC and Polyethylenes are weldable[though UHMW is very difficult]. Problem I've found welding PVC is the objectionable and even dangerous fumes given off, so I try to stay away from it. PVC is also more brittle than Polys. Early on I welded poly pipe with a simple soldering iron then graduated to a heating tool and filler rod. One very important thing in welding poly is to thoroughly scrape the surfaces to be welded to remove any oxidation. Another important thing is to not get the surfaces too hot or you'll draw the wax [yes, polys contain wax] to the surface and the bond will be weak.

Steve Herschbach
01-11-2013, 06:55 PM
From http://en.wikipedia.org/wiki/Marlex


Marlex is a trademarked name for crystalline polypropylene and high-density polyethylene (HDPE). These plastics were invented by J. Paul Hogan and Robert Banks, two research chemists at the Phillips Petroleum company.

Marlex was used by Wham-O for their Hula Hoops in the 1950s, which helped create a market for this plastic. It is now used surgically as a reinforcing mesh in inguinal hernia repair.

peluk
01-11-2013, 11:44 PM
Thanks for the info, gents. In answer to Marshall's point about a highbanker hopper,consider this.If you go to one of the building supply stores,check out the largest plastic tub wheelbarrow kit with the dual wheels.If you take the tub and cut out the bottom of the back wall(end closest to the handles),you could mount grates/grill in there with a wooden or aluminum base plate that extends out the rear just short of the grill.Raise the tub up and set at the desired grade.Put your choice of support structure in place with the two supplied rails as the lower sluice supports with cross bars where desired.Alter the wheels with a longer axle.Make an aluminum(or wood) sluice bed,install mats and expanded or whatever.
That leaves only the spraybars to fashion.The sluice may be 20" wide when finished with lots of capacity especially if you put more mat etc in the tub base.
You can wheel it where you want and even make the handles to fold down out of your way.

Now the question.I bought a set of yellow Keene pontoons today.They are used but were stored inside and have no cracks or crazing.Would I be wize to paint them a darker color to protect against sunlight?

LipCa
01-12-2013, 07:10 AM
My son made some plastic dredge boxes while in New Zealand dredging with TrevNZ. When he got home here in N. Ca. he got a plastic welder and made a highbanker out of ABS. It welded up very good.
He's in Nome now. Maybe he'll pop in and comment.

overtheedge
01-12-2013, 11:00 AM
... check out the largest plastic tub wheelbarrow kit with the dual wheels.

Thank you peluk. So many ideas just pounced on me.
eric

peluk
01-12-2013, 03:05 PM
There are so many different plastic formulas for containers,I generally look for those closest to Tupperware in performance.That's a product that's resilient and durable.The Coleman canoe was similar in performance but I noted it expanded in the Sun's heat.Not a big deal for us because cool water brings it back in shape.
I look for plastic trash barrels,and waste baskets but I've also salvaged cracked mortar tubs.This is why. The head end of the highbanker's lower sluice creates too abrupt a change in flow from the upper hopper floor.This makes for bubbles at the very least and negates any laminar flow action that may have developed. The answer is this....

Look for a radiused section in any container that will fit nicely into that top end of the lower sluice. I have a plastic section in every small cleanup sluice and every highbanker I own,at that location in the flow.

Another is this. I make a slick section to tuck under the plactic section and run it up the walls on either side of the sluice.The mats that follow tuck in under it and they also ride up the walls.This ensures the material and flow does not get under the
mats. The transition from hopper bed to lower sluice is smooth and more conducive to quick separation and laminar flow development.

Cleanup is a breeze and recovery is assisted to the maximum.

LipCa,any visit with your son is a trip.He's a gogetter.