Joining 3D Printed Parts

[Ian Jones]

I've heard of ABS slurry, what's that?

What about adhesives for PLA?

What about interlocking parts?

So many questions!

Edited By Ian Jones on 18/10/2016 16:21:19

[Trex700e]

Yeah ABS slurry is good for keeping an ABS part onto the print bed but it is not good for sticking two parts together.

For joining ABS or PLA I have always found a contact adhesive like UHU Por to be best. Any glue that when cured still has a bit of flex in will work wonderfully. 2 Part epoxy usually cracks along the join line.

I hope this helps.

[Ian Jones]

Thanks T. but what is the slurry and where do you get it. At the moment I'm using DLAC on the print bed, as suggested by Allen Bowker, pricey but it's working very well.

Today I've been trying my hand at friction welding, using a piece of filament in a dremel. The first attempt worked but I easily pulled it apart. In the second attempt I used a higher rpm on the dremel and made sure the filament melted into the join. It was better, I couldn't pull it apart but a little tap with a pin hammer made it fall apart. This doesn't appear to be a good method for weight bearing or stressed parts... or am I doing it wrong?

[Andy Meade]

Conversely I've been using slurry to join ABS parts for a couple of years - works well. You need a good amount, and the parts benefit from being "squidged" together - press and gentle twist into position. Any failures (via "arrivals" or testing) I've had of parts bonded this way have always been the structure, rather than the joins.

[Ian Jones]

Thinking about something like a fuselage printed in two or more parts, it's crucial that it remains straight. When the faces are "squidged" together is there any collaping of the material that might make a banana shaped fus?

[Ian Jones]

I've had chance to follow up on Andy's suggestion for ABS and I too have found it works a treat. A thin coat of acetone on both layers seems to work well for me. I've also tried using small quantities of slurry with similar results.

There's loads of YouTube videos about making slurry and they seem to involve using a fair amount of acetone then adding ABS to it. So far I haven't needed such quantities and found that melting ABS debris from the printer by adding sufficient amounts of acetone to achieve the desired consistency has worked well.

[eflightray]

Just a thought, but isn't there a 'solvent' adhesive for most ABS/PVC type plastics sold at DIY stores for plastic pipe plumbing etc. Evo-Stik do one called Pipe Weld.

[Ian Jones]

Ooooh, so there is, anyone tried it (Pipe Weld)?

[BobW]

Quite a few model shops sell Plastic Weld Cement which is a watery solvent for polystyrene sheet, acrylic and ABS. I haven't used it for ABS but it works really well for sticking PLA . Very good for PLA repairs and solvent gluing parts together

[Ian Jones]

Good to see some more solutions coming in.

I recently printed some ABS test ribs for Bob Hynes and he tried bonding the trailing edge with cyano and light pressure. I had only previoulsy tested ABS to ABS with cyano and it wasn't succesful so I was surprised when Bob's test was absolutely solid, the wood giving way, not the joint.

Edited By Ian Jones on 03/02/2017 19:02:14

[Nigel Luther]

Slurry as I made it was based on bits of plastic from the 'sprues' (left after parts removed) ... dropped into MAK Plastic Weld ... then use a paint brush to apply.....

Its the way 'clean' joints are made of plastic display models ... and for really fine work - just the MAK by fine brush without sprue ..

 

Nigel

Edited By Nigel Luther on 04/03/2017 17:10:29

[Ian Jones]

I might try one of the solvent/weld adhesives but at the moment for ABS I'm happy to use acetone for good fitting joints. For minor gap filling in joints I make up a slurry of acetone and the same colour scap bits of ABS.

Nigel, I can't find MAK plastic Weld, the suearches I've done all seem to show extruders, or have I misunderstood?

[David P Williams]

I think it might be MEK - Methyl Ethyl Ketone

[Denis Watkins]

It is as you say METPAK, the tradename, and works by capillary into close fitting parts, and is very fluid like water

The fluid dissolves the surfaces, then they can bond as it evaporates

Edited By Denis Watkins on 09/03/2017 12:57:45

[onetenor]

Plumbers cement , MEK, a liquid cement called Plastic Magic, Acetone ,Amyl acetate Mixtures of them .They all seem to work. Also Chloroform if you can get it.As ever TEST TEST and TEST again

[onetenor]

Plumbers cement , MEK, a liquid cement called Plastic Magic, Acetone ,Amyl acetate Mixtures of them .They all seem to work. Also Chloroform if you can get it.As ever TEST TEST and TEST again

[Robert Armstrong 2]

UHU Por seems to have worked quite well for PLA, though the parts have only been together for a few days and are not subject o much load. I tried thick cyano on two bits of the raft offcuts, with poor adhesion. Might have been better with kicker?

[Ian Jones]

Posted by Robert Armstrong 2 on 30/03/2017 08:47:49:

UHU Por seems to have worked quite well for PLA, though the parts have only been together for a few days and are not subject o much load. I tried thick cyano on two bits of the raft offcuts, with poor adhesion. Might have been better with kicker?

I think cyano is used for PLA quite a lot but I don't know how good the join would be under stress, especially if kicker is used.

Anyone stress tested any of these methods?