Plastic Welding

Luke · Criminal Joined: 27 Apr 2003 Posts: 94 City: BAY AREA!!!

Anyone on here have any experience plastic welding?

Was looking at making up some hard tanks for my boatand was gonna custom weld them with some sort of plastic.

Recommended plastic welding gun?

Recommend type of plastic to use for tanks?

Any other pointers....

boarditup · Addict Joined: 01 Dec 2003 Posts: 731 City: Allendale, MI

You need High Density Poly Ethylene (HDPE). It is welded by heat. You can rent the tools from an HDPE supplier. If you are thinking this will be cheap, you are mistaken. It takes a lot of skill to use this equipment and the plastic is not cheap either. It may be similar in cost to have them welded locally in aluminum, which is a much more common material to work with. You also can have you tanks custom fabricated by one of several businesses that specialize in this type of constuction. Forrer out of WI is one example. I have used them for several custom fabrications over the years.

If you want more info off line e-mail me at rider@boarditup.com

Luke · Criminal Joined: 27 Apr 2003 Posts: 94 City: BAY AREA!!!

Why high density, what about low density?

I was already looking at high density and found what I thought to be decent prices online at www.usplastics.com

I will look for a plasitics dealer around here that rents equipment,

Anyone know of a company in Nor Cal that rents plastic welding equipment?

boarditup · Addict Joined: 01 Dec 2003 Posts: 731 City: Allendale, MI

LDPE won't weld good enough. HDPE is the only way to go. You may have to use internal bridging to prevent bowing. That is why it is somewhat complex.

Don't use anything thinner than 1/4, 3/8 prefered. That way bridging is not an issue.

As far as fabricators, look up one of the environmental construction companies. We use it all the time.

Luke · Criminal Joined: 27 Apr 2003 Posts: 94 City: BAY AREA!!!

Cool thanks for the info, I was already price out the HDPE anyway. Figured their had to be some bad point about the Low density,

I had already planned to put in some sort of cross bracing as it would help eliminate sloshing and strenghten it.

When you say enviormental what should I be looking for in the phone book? I know the plastic fab places around here are really high-tech or a place liek TAP plastics, who won't even garuntee it wont leak. What good does that do me.

I priced out welding guns and for a low ender its around 250 and 600 for some median priced ones. Got any specific info for a good gun for poly?

Thanks

bigasswake · Outlaw Joined: 25 Jan 2004 Posts: 129 City: Colleyville

Why not just an ABS welder? Its what is used on dashes and many other things.

Kent and Carol · Newbie Joined: 18 Sep 2003 Posts: 9 City: Seattle

luke, I dont know anything about wielding the tanks but an Idea for you might be to alter an existing tank. I got my 40 gal tanks off ebay for what I thought a reasonable$70 ea. delivered. ebay has what I found to be 20,30 and 40 gal in rectangle shape.jsut search for "water tanks"
good luck...knc

Luke · Criminal Joined: 27 Apr 2003 Posts: 94 City: BAY AREA!!!

Already though about that, but decided the best way to take up space effiecntly would be to make my own tanks. This is because the wall on the inside of my boat cuves out and I can fit a bigger tank if I make it myself.

But maybe just for ease I will look into different size tanks, I know you can get any size you want.

boarditup · Addict Joined: 01 Dec 2003 Posts: 731 City: Allendale, MI

e-mail me your e-mail address and zip code. I have a directory at my office and should be able to track down a fab shop quickly and e-mail you back.

rider@boarditup.com

wesgardner · Posted: Mar 13, 2004 5:23 pm Post subject:

Hey Luke,

We used to lay up fiberglass tanks...we used a sheet of plam (that's Formica - plastic laminate) layed out very flat on the shop floor with mold release wax on it (or car wax). We then layed up layers of cloth/roving/mat to what ever thickness suits you. Once cured you can pop the panel off the plam, cut to shape, tape the seams and voila! tank of any size and shape fairly cheaply. Install thru hulls or glass in tubing for connections - you do want baffles in the tank if they are of any size... to make one side "boat shaped" just let the plam take the shape (approx) and lay it up

Wes

Pumpkin Head · Outlaw Joined: 01 Aug 2003 Posts: 127 City: Oregon

Luke,

I do a bit of poly welding at work on HDPE and PVDF. Just repairs and small projects. No major fabrication work. A good hot air welder can be quite costly. I personally perfer the Leister Diode welder. It runs about $900 at Harrington Plastics. You can get a fairly crappy new torch for under $300. Haven't ever looked on E-Bay. Making good strong poly weld joints takes a bit of practice as well, especially if you want them to look good. As you can see, its more than likely worth the cost and saved effort to have someone else do the fabrication for you.

wzen animal · Criminal Joined: 21 Sep 2003 Posts: 98 City: wiltshire

have a look on ebay u get some good tanks on there 4 a cheap deal.

boarditup · Addict Joined: 01 Dec 2003 Posts: 731 City: Allendale, MI

In your area, there is an ISCO branch. They are one of our suppliers for HDPE.

www.isco-pipe.com
800-345-ISCO

As a last resort, I would recommend Forrer Supply in Germantown, WI. I have used them the most and they have done quite well for me. It will cost a lot to ship, however, due to weight and size.

Both of these companies are used to commercial accounts and may raise an eyebrow on a consumer purchase and will require payment up front and specs.

Thinking about your design, I would recommend that you spec out perforated vertical pipes welded inside the tank. This will prevent sloshing, provide structural integrity, and still promote quick emptying. This is a design that the military uses for special ops water tanks.

Good Luck