# Harbor Freight Plastic Welder



## Doomsday Cult Leader (Mar 21, 2007)

On the Halloween Forum, I said I'd post my results with that Harbor Freight plastic welder http://www.harborfreight.com/cpi/cta...emnumber=41592 and the addition of a voltage regulator. I think some folks here might also be interested, so here it is.

I used a Staco variable autotransformer model 3PN1010B 0-140 Volt 10 Amp 1.4 Kva. 
I'm sure there are much cheaper regulators with the same capabilities, I got this one for free.

I also had to swap out the pressure regulator to one that could control the pressure better and lower than the Chinese no-name POS that came with it.
I used a Norgren # R07-200-RGKA pressure regulator, this will reg below 1 psi, again, this was free.

I'm only moderately satisfied with the results, but I do believe practice will make me better and I'll eventually get decent welds.

I did most of my testing between 30 and 75 percent voltage and at less than 1/2 psi. 
By lowering the heater temp I could lower the air flow and keep from blasting the plastic away from the join.
I achieved various results, but with any welding there is some art to the science, and I didn't expect to find the perfect settings.

I tried welding a Mr Thrifty, and had a hard time keeping from scorching the surface at first. I finally ended up with a serviceable weld that needed to be painted and required a fair amount of prep work. I had to have a pretty good fit because I couldn't get a "molten puddle" of plastic. I had to use a lot of filler to get the pieces to adhere.
I then tried welding a Bart. Much better results. I could achieve a sticky semi-molten surface without scorching, fairly easily. I could press an ill-fitting joint together and have it stick without having to do a lot of prep fitting.

The Mr Thrifty was the same plastic that Buckys are made of, Marilyn told me she thinks it's polypropylene. 
The Bart is obviously a different type of plastic. It's much smoother and glossy looking.

I did not try welding PVC! I just didn't have any lying around.

The conclusion I arrive at is that it's a viable process, although I don't think it's any faster than epoxy, in the long run it will be cheaper. 
I think as far as strength goes, epoxy is probably a better bet. But, the Bart welds seem strong enough to more than support their own weight.

I was hoping to find a cheaper alternative to epoxy, I don't think this is it.


----------



## Lilly (Jun 13, 2006)

thanks for info Doomsday..


----------



## Dr Morbius (Sep 21, 2004)

With epoxy at only 3 bucks a syringe, it seems cheap enough. I don't know why you wuld need a cheaper alternative, unless you need ALOT of epoxy!


----------



## Doomsday Cult Leader (Mar 21, 2007)

I like to make free-standing skeletons... with no visible hardware.
Yeah, LOTS of epoxy!

You're welcome!


----------



## BooGirl666 (Jul 29, 2006)

the link doesnt work but great info... thanx


----------



## Sickie Ickie (Jun 20, 2006)

DDCL, thanks for your results. I think it helps everyone when people try new things and share the results!


----------



## Lilly (Jun 13, 2006)

try this link babygirl ...there is something missing in the first link above thats why...it looks same here but it is dif

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=41592

it is item number 41592-1VGA


----------



## Revenant (Mar 17, 2007)

Welding gives the strongest and least intrusive bond with any material, plastic included...the tool in question is a Harbor Freight cheapie. If you had a professional one like a Wegener you'd get a lot better results, but who wants to spend hundreds of dollars for something you only use on a few things once every year? (Wait a minute, forget I said that:googly: )I've chatted with a cpl of ppl who've used the HF welder and they all said it takes a lot of practice to get decent welds with it. Practice practice and make sure you have sticks that match the material you're welding.

Please keep us posted Doomsday...I'd love to get a plastic welder but I can't see spending the money on a "real" one... that HF toy costs couch change and might be "good enough"!


----------



## Doomsday Cult Leader (Mar 21, 2007)

Thanks for fixing that link Lilly!

What I'm hoping to achieve is that ever elusive "invisible" support. I like completely free-standing "in the round" type props.
That's why I put far too much time, effort, and money, into everything I make!

Revenent, if you look up the prices of the components I added/switched, you'll find I'm getting pretty close to "pro prices"! 
But, as I said, I got 'em for free.

I've been working 12.5 hours a day since Jan 1st, (only 8 on Sat. woo-hoo! Sun. is laundry, groceries and catching up on some sleep.), so I'm not getting a lot of time to do the things I want. An update may be a while in coming.

I can weld steel, and I did notice an improvement in the short time I spent on the plastic. I'm certain a decent plastic weld can be done.


----------



## Lilly (Jun 13, 2006)

Yw , doomsday,
yup practice makes perfect and time really doesnt matter, better safe than sorry..
I like it when people try something and let us know how they work and such.
Would you have any pics of your experimenting perhaps? That would give us a good idea of what is going on then.


----------

