[Shop-talk] Repairing plastic - weld or glue?

[Brian Kemp]

Jim - It all depends on the type of plastic.  See if you can find the 
recycle triangle with a number in it on the back of a similar piece then 
look that up.

If it is a clean break and a plastic that responds well to solvent type 
glue, that is probably the best bet.

As to plastic welding, you may be able to use a soldering iron. I've 
used a 30W for fine stuff and a 100W pencil iron with a flat tip for 
bigger things.  If you want a more precise temperature control, use a 
dimmer controlled outlet.  If you go this route, you are going to need 
donor plastic and then do some cleanup.  I would guess that this is not 
a match for your application.

If you do try welding/melting, try a scrap of similar plastic first, 
maybe from a broken toy.  Some melts nice.  Other plastic just turns 
into hard brittle goo.

Melting did work well for my plastic gas tank on my B&S lawn mower gas 
tank.  Mowing around a tree, I hit a branch in the wrong place and 
cracked the tank.  I drained it, rinsed it with water, then let it dry 
in the sun.  It was black plastic, a little flexible and slightly 
slippery.  I forget the number now.  I had some similar plastic from the 
packing of kids toys that I used as my solder or welding rod 
equivalent.  I heated up the plastic and made a mound then blended it 
all together.   This was much more economical than the $75 I was quoted 
for a replacement tank from a local vendor. When you finish, wipe the 
iron tip with a wet sponge, then clean it with flux and re-tin it and it 
will be like before.

You might also want to call some appliance repair places in your area.  
If you get lucky, you might find a guy that collects used parts and sell 
you one cheap.  I was able to go this route for some spa cover clips.  A 
local service place always cut the clips off old covers because they get 
broken fairly often.

Brian


On 3/18/2013 7:43 PM, Jim Stone wrote:
> The plastic catch that holds the door closed on my refrigerator recently
> broke.  While it isn't necessary to the question I am about to ask, there are
> photos and more details about the broken part here:
> http://forum.appliancepartspros.com/refrigerator-freezer-repair/519815-broken
> -door-catch.html#post803233
>
> GE, in their infinite wisdom, doesn't sell a replacement catch alone; you have
> to buy a new door seal.  Nor to they even sell just one side alone (it is a
> side-by-side fridge); you have to buy both sides for $225!  That is a heck of
> a lot of money to spend for a small piece of plastic.  So, I would like to try
> to repair this one before shelling out for the replacement pieces.  I have
> never had much luck gluing plastic, even with glues said to be made for it.
> And, the fact that this piece is under stress every time the door opens and
> closes (let alone the fact that it failed under such stress) doesn't give me
> much confidence in glue.  Still, if there is a glue or solvent that someone
> here knows of and thinks I should try, I am all ears.
>
> My other option is to purchase a plastic welder, something like this:
> http://www.harborfreight.com/plastic-welding-kit-with-adjustable-temperature-
> 96464.html  I have been interested in buying one of these for a while, and
> buying a $50 tool I can use again vs. paying $225 is a no-brainer, if this has
> a good chance of working.  Does anyone here have experience with one of these
> or a competitor's product?  What are the odds of my being able to join the two
> pieces together well enough to stand up to repeated openings and closings?
>
> Thanks.
> Jim
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