How to DIY weld plastic

How to fix plastic without glue.

How to do DIY plastic welding. A DIY guide on how to weld many kinds of easily at home with just a cheap soldering iron.

Recently one of our veranda chairs had a broken plastic arm.
In that moment, we could have thrown it away as there would be no spare part for it.

Or fix it

One screw needed to be replaced and that was easier than expected.

Biggest problem was the plastic handle was broken and it was important to have a strong bond if I was to fix it.

Thought about using glue such as Super glue or epoxy but usually in these cases glue just doesn’t work.
Even after leaving it for 2 days to cure, it will break.

Next best thing and the only way to fix it is to weld the plastics.

Welding plastic

When melting plastics, always have a way to get rid of fumes, a fume extractor or doing it outdoors next to a fan.

The soldering iron is used to melt both sides of the cracked plastic then you can use another piece of plastic as filler to make the plastic bond stronger.

Plastic parts nearly aways have the plastic type code written on them. Usually it’s is a hidden place.

Few types of plastic that are easy to weld are:

PP – Polypropylene
HDPE – High-density polyethylene
LDPE – Low-density polyethylene

In my case the arm of the chair is made of PP or Polypropylene.

I used water bottle caps as filler to make the melted plastic joint thicker and more solid.

Let soldering iron and the welded plastic part cool-down to room temperature.

Once cool, the plastic is fixed and ready to use.

No more 24-48 hours waiting for glue to get dry.

Weld plastics, don’t glue them.

Like that it’s harder to break in the future.

Fix many things

Used the exact same DIY hack to fix a standing fan that had a plastic piece broken.
The holder of the fan grill was broken and is now solid in place.
The fan is otherwise a great product but it had this design flaw.

Fix things instead of throwing them away

It would be a real shame to throw away a perfectly working appliance or household item just because a small plastic part is broken and there are no spare parts available.