Classic Winnebagos & Vintage RVs

Topic Boards => Info Articles => Topic started by: DaveVA78Chieftain on March 04, 2012, 09:21 PM

Title: Harbor Freight Plastic Welder Kit
Post by: DaveVA78Chieftain on March 04, 2012, 09:21 PM
(http://www.harborfreight.com/media/catalog/product/cache/1/image/370x/9df78eab33525d08d6e5fb8d27136e95/i/m/image_20221.jpg)

http://www.harborfreight.com/plastic-welding-kit-80-watt-iron-67102.html (http://www.harborfreight.com/plastic-welding-kit-80-watt-iron-67102.html)

While the idea is good unfortunately they selected to low of a grade 80 watt soldering iron with a small screw tip.  The portion of the tip that screws into the iron is to weak and breaks off in a relative short period of time (combination of heat and pressure).

Solution:  Get a Weller SP80 iron that has a larger diameter tip.
http://www.ebay.com/sch/i.html?rt=nc&LH_PrefLoc=2&_nkw=weller%20sp80&_fln=1&_sop=15&_trksid=p3286.c0.m283 (http://www.ebay.com/sch/i.html?rt=nc&LH_PrefLoc=2&_nkw=weller%20sp80&_fln=1&_sop=15&_trksid=p3286.c0.m283)

If you are repairing a water tank that is white in color, then go down to your local hardware supply store and pick up a role of Polyethylene tubing (used for supplying water to an ice maker) for the plastic solder.  Would also use that tubing if repairing a grey/black tank made of Polyethylene (white in color).   If repairing a black/grey tank that is black in color (ABS), then buy a piece of ABS pipe and use your knife to make some ABS shavings to use as plastic solder.  The key for the plastic solder is that it has to be of the same material as the part being repaired.

You tube of a ABS bike rim being repaired.
http://www.youtube.com/watch?v=NuA6d49Z7Rc (http://www.youtube.com/watch?v=NuA6d49Z7Rc)

Please be aware that for plastic water tanks, Winnebago embedded a nut into the tank that they then screw a metal right angle bracket into that is also screwed into the floor.  With age, radial cracks appear around these attachment points which turn into leaks.   You need to drill small holes at the end of the crack (prevents crack from running any farther).  Cut a piece of aluminum window screen as reinforcement then embed it into the plastic using the soldering iron and plastic solder (make a patch).   Not hard to turn the part and the plastic solder into paste (not liquid) which is relatively easy to work.  This forms a strong patch using the same material the tank is made of.

Dave
Title: Re: Harbor Freight Plastic Welder Kit
Post by: ClydesdaleKevin on March 04, 2012, 10:12 PM
You can repair an ABS plastic tank, black in color, even easier than welding it.  All you need to do is shave some ABS shavings from a piece of ABS pipe, and get yourself a can of ABS cement...it has to be specifically for ABS, and is black in color, not the multi-use stuff.

Now, take the can, and mix in your shavings.  ABS is already a mixture of ABS dust in a solvent solution.  Add more shavings to make it even thicker...Now paint it into the crack/cracks.  Let it dry, and keep building it up in layers.  If you are patient and use MANY coats, and just keep layering it on, you can fill in cracks and even thicken areas of your ABS tank that seem too thin or weak.  What you are actually doing is adding layers of ABS that, from the solvent, bond to your tank as if it were part of the tank from the get-go.

Make sure you let each coat dry completely before recoating.

This is how we fixed our tank in the Nautilus, which had a HUGE crack on the bottom and around the outlet fitting.  It hasn't leaked since, even after a LOT of road miles and use.

You can even fix an outright HOLE in your tank this way.  But you'll need to find a sheet of ABS plastic bigger than the hole, about the same thickness as your tank, or a little thicker.  Apply ABS cement to one side of the sheet, and glue it in place.  Once its dry, coat all along the edges in layers, letting it dry between layers, and keep building it up until its thick and even along the outside of the patch piece edges. 

It works great, without welding!  Although technically, I guess you could call my process a chemical weld.

Kev
Title: Re: Harbor Freight Plastic Welder Kit
Post by: ClassCKing on March 04, 2012, 11:59 PM
ahhh i remember mine $@!#@! and it was in the garbage the next day.found one at the local welding supply shop..well worth it..you can buy the plastic rods from 1ft to 3ft.the rods come in a couple different thickness of course you cut them down as needed.the heat gun is similiar to a small slender blowdryer like the heat gun for heat shrink tubing but hotter..melts the plastic faster more even with more control.more money but less headache and  with patience does the job.