ABS Plastic Welding and Gluing.

Ex850R

I gleaned some more knowledge on how to join and fill then finish my abs headlights conversion. Here is a post I.found.

Start with 100% pure Acetone, buy a gallon.
Pour an ounce or so into a glass jar (small open mouth jar). Take a scrap grill and using something sharp, scrape off peelings (like pencil shavings size) into the jar of acetone. Put allot of shavings in, the acetone will gradually melt the plastic into a goo. Add enough plastic until the goo reaches toothpaste consistency. Once you have a good batch melted put the lid on the jar tightly and set it aside. Now, prep your grill as normal, V out cracks on both sides, etc. Use clamps near the joint to align the two sides flush and parallel. Smear on some plastic goo, leave it crowned up over the crack like a regular weld looks, let it cure overnight. Sand to flush the next day, fill any pinholes with JB Weld. The crack will practically disappear at this point, paint as normal

3m 8115 panel bonding adhesive works too.

I have used a product by devcon called plastic welder,it's a two part in a a syringe style dispenser.

Sand as you would a soft wood with very fine grit although you will never match the surrounding heated cast for of the original.
Les.

nickm

so this bonds like filler?

PaddlerEd

Also any cracks are best stopped with with a hole at each end, so that the it 'stops' the crack spreading.

My ABS repair comes from welding canoes and kayaks, some of which are ABS others are PE. The big thing is to try to get the same plastic, ideally from the bit you are trying to repair as it will be exactly the same make up chemically.

Ex850R

It evaporates so gives similar deposit as what you are joining , not as strong structurally , mesh would be a help as you have mentioned in welding it. I will give it a try when have a chance , need correct filter for me air fed welding / grinding kit (Adflo ) or filters for my mask but I prefer the full face Adflo at this point. Nasty stuff....

Thanks Ed,any extra information on is good here!

egads (she/her)

Your lego as a source of abs tip is also handy as.

PaddlerEd

I'll see what else I can dig out... when you see some of the cracks that welded in kayaks you'd be surprised!

PE (polyethelene
Here's a link on welding PE plastic from one of the manufacturers

I know of this guy (I recognise his name from the UK kayaking and canoe forums) so trust his advice, that and the fact he is a high level coach, but it gives you an idea as to what can be welded, and how to do it. (PE again)

With PE there are a couple of different types; there's linear PE and crosslink PE. Linear can be welded easily, crosslink, whilst intially stronger can't be welded.

ABS:
Not so much easy to find stuff; the ABS is normally a layer in a material called Royalex (which has now gone out of production; it was originally used in aircraft seats)

Here's a good load of links that might help with plastic welding... I forgot how odd canoeists and kayakers are...

OldnDecrepit

I have a cracked headlight cover on my 740 GLE.

How do you recommend I glue up this crack so that it doesn't get worse?

PaddlerEd

Drill as small a hole as you can in the end of the crack to stop it spreading; then with the shavings melt them in some acetone and then use that as a paste to fix the crack, you'll need more shavings/plastic to do it properly. Is there any way you can shave a bit from the edge of the headlight cover to use?

OldnDecrepit

Well I probably could shave one of the edges. I have a broken piece of a bonnet protector from my Magna I could use assuming it's the same stuff.

Do I need pure acetone? What about some of SWMBO's nail polish remover?

Ex850R

Purer the better,as it has to boil off out of the mixture so it sets, keep it in airtight jar if using a lot.