Huge Welding Job

[farmersamm]

Can he weld it???????????????????

Roofing tar didn't work......................

Cleaned it off with paint thinner.....................and we gots a crack

Never actually knew where it was, just slopped tar on it.

In the finest tradition of regular welding........drilled the ends of the crack(although I don't know if it's gonna matter once I get after it with a die grinder(shrug)

Bit o' cleaning................................................................

Searched a full day for this thing. I bet I bought it maybe 15yrs ago. Never used it. Anyways, found the lil' gem. Figure out in the next few days if I can use it for anything but a doorstop.

About the most important information in the whole deal..............what kind of plastic it is, which equates to what kind of rod to use. Don't have any reinforcement steel mesh on hand, so just gonna wing it, and hope it holds. If not...........we'll just melt her again.

Probably get after it tomorrow.

 

[used red MN]

What is it, cab top?

 

[rustred]

who is he?, what is it, what metal is it ?

 

[DoubleO7]

HDPE stands for "High Density Polyethylene"

V-groove the crack, a high power soldering iron can be used as the welder.

If possible find a spot on the object you are repairing to slice off a dliver of the plastic. Maybe like a mold seam or an outside corner, etc.
That way your filler rod material is for sure the same type of plastic.

Lots of utube vids on welding HDPE tanks, etc.

 

[used red MN]

who is he?, what is it, what metal is it ?

what kind of plastic it is,

??? … not metal

 

[super99]

Water tank???

 

[Larry986]

Looks like a Rubbermaid water tank. Got one out back that we never did find the leak.

 

[hurleyjd]

Looks like a Rubbermaid water tank. Got one out back that we never did find the leak.

Linex dealer lined three for me $65 each.

 

[Mark-Ia]

I saw a video on utube that a guy used zip ties as filler{rod} to weld plastic with one of those plastic welders.

 

[Fritz Maurer]

Can he weld it???????????????????

View attachment 95296
Roofing tar didn't work......................
View attachment 95297
Cleaned it off with paint thinner.....................and we gots a crackView attachment 95298 Never actually knew where it was, just slopped tar on it.

View attachment 95299
In the finest tradition of regular welding........drilled the ends of the crack(although I don't know if it's gonna matter once I get after it with a die grinder(shrug)

View attachment 95300
Bit o' cleaning................................................................

View attachment 95301
Searched a full day for this thing. I bet I bought it maybe 15yrs ago. Never used it. Anyways, found the lil' gem. Figure out in the next few days if I can use it for anything but a doorstop.

View attachment 95302
About the most important information in the whole deal..............what kind of plastic it is, which equates to what kind of rod to use. Don't have any reinforcement steel mesh on hand, so just gonna wing it, and hope it holds. If not...........we'll just melt her again.

Probably get after it tomorrow.

What kind of gas do you run through that thing?

 

[Jim.ME]

What kind of gas do you run through that thing?

Hot air, no gas. It is basically a concentrated heat gun.

 

[Fritz Maurer]

Hot air, no gas. It is basically a concentrated heat gun.

So you just like hook it to an air compressor?

 

[Jim.ME]

So you just like hook it to an air compressor?

Some like that used just compressed air, some could use a gas, nitrogen I think they used, for some types of plastic.

 

[farmersamm]

Looks like a Rubbermaid water tank. Got one out back that we never did find the leak.

I wouldn't have found the crack if it wasn't for the failed roofing tar we put on it. The paint thinner, and residual tar in the crack, highlighted the crack.

I believe, now that I've seen how difficult it is to locate the cracks on these Rubbermaid tanks......................I'd use this https://www.rocol.com/products/crack-detection-developer-spray Spray on the dye, and then the powder. Used all the time when looking for defects in steel. This stuff can be used on plastic so they say.

BTW.....I believe this tank is over 20yrs old(not sure by any means), and has done remarkably well over the years. I MISS THE RUBBERMAID GAS CANS. My old ones are still going strong.

 

[farmersamm]

Looks like a Rubbermaid water tank. Got one out back that we never did find the leak.

I remember when WalMart killed Rubbermaid.

The Rubbermaid story starts at 11:42

 

[farmersamm]

V'd with a die grinder. Be careful.........this ain't steel It'll go deep in a heartbeat if you aren't careful.

Starting to fill the bevel, same as welding steel. I'm not crazy about this process, mostly because I've never done it before. IT'S HARD TO GET THE FILLER ROD, AND PARENT MATERIAL, TO MELT AT THE SAME RATE. Takes some practice.

Halfway filled. By this time I'm using a screwdriver blade as an iron to attempt to smooth it out as it's laid in.

Filled to final level(almost). I need to make a flat tool for smoothing it better than possible with a screwdriver. The small electric welders that resemble a soldering iron come with a triangular iron...............they might be a better finishing tool.

I need to fill in some porosity to finish out, then water test it. This process is harder than I anticipated. I'm used to welding steel,, which has a better controlled puddle.

Although the dial face is a bit scratched..................I'm running at 3psi shop air. I might experiment with different settings to try to adjust heat output, just for S&G's.

EDIT: Looking at my pics,, I see a bit of the crack that didn't get welded. Good thing about pics, sometimes you see stuff that your eyes didn't see while you were working.

 

[Janicholson]

You are doing very well. It is easier as your experience grows. I have taught it in my plastics classes. Jim

 

[NoDakInMN]

It's been a while, but I used to weld sch 80 PVC quite a bit. IIRC it went better if you treated it more like you were gas welding, but at lower temperatures.

 

[farmersamm]

I FIGURED IT OUT

​

The trick is to SHOVE the rod into the puddle.
Hold the rod vertical, heat both the parent material,
and the rod, with an up/down weaving motion.
Stay in the middle of the joint.......Don't stray to either side.
DON'T DWELL
ONCE IT'S MELTING KEEP MOVING
This way you get good fusion........both surfaces are equally heated.
Move the rod towards you as you melt, same with the gun.
Let the puddle follow.​

 

[farmersamm]

You are doing very well. It is easier as your experience grows. I have taught it in my plastics classes. Jim

Thanks for the encouragement