PLA Adhesives

I'm a big fan of the Duco Cement. Smells like it might give you California in cancer but should be safe everywhere else. I think you follow my layout build and 3D printer builds so you see some of what I glue together. I glue some thin sections together and it does a good job.

I gotta admit, I haven't had much luck with small cross sections and CA glue. I haven't looked up the chemical reaction but it almost seems like it needs a lack of oxygen to work well or something because it tends to work for me when I push two bigger flat surfaces together but doesn't seem to set when it's on an outsider surface. Could just be the operator though hard to say.

Thanks Bill!   Yup, on the oxygen... tried using a homemade accelerator (water & baking soda) and it hardened the CA, made a mess and still gave way.  I'll grab some Duco!

No personal experience with either.  Several sources recommend Weld-On 16 or hot glue for PLA.

https://www.reddit.com/r/3Dpri...this_case_for_a_pla/

https://www.instructables.com/...LA-3D-Printed-Parts/

https://store.creality.com/blo...FakZ1aQaAsWsEALw_wcB

I'm skeptical of using any CA for parts that have a minuscule contact area.  I have tried Loctite, Gorilla & Super Glue... all to no avail.  As Bill said... the larger pieces are absolutely fine.

I never heard of Weld-On 16. I wouldn't mind checking it out. I use the hot glue gun on the low temp setting for temporary fit up. The high temp setting definitely does a good bonding job.

I use Plastruct Bondene quite a bit.

PLA is soluble in dicholomethane, aka methylene chloride. Micro Mark sells “ Same Stuff” which is or was Methylene Chloride. Some of the Plastruct adhesives may also work.

https://micromark.com/products...keyword=same%20stuff

Pete

OK... Duco & Jethro BODENE ordered!  Thanks Norm!  I just dug out some 3M Black Super Weatherstrip Adhesive from the shed.  I've used it on the old Mercedes and it's super sticky and works very, very well on the cars.  I stuck a couple of flanges on the tank with it... let it setup for an hour and see what happens.

The trick to using CA is it has to have a tight fit, any gaps are a problem unless you're using a gap filler type like Loctite 380 or Loctite 480.

All of the plastic to plastic and metal to plastic joints in this crude oil loading platform were made using Cool Chem Integrator 2.0.  It has been my go-to scratchbuilding adhesive for years.  Click on any photo for a larger version.

https://coolchem.com/

The surfaces are pretty darned smooth... I can not see or feel any gaps.  Both the Tank End & Flange Neck (contact surfaces) are printed on the Smooth PEI plate.  I can easily scrape off the cured CA from the surfaces... there appears to be a lack of 'grip'.  Attaching 5mm diameter and up is not a problem... 4, 3 and 2mm are an issue.

@Bob posted:

All of the plastic to plastic and metal to plastic joints in this crude oil loading platform were made using Cool Chem Integrator 2.0.  It has been my go-to scratchbuilding adhesive for years.  Click on any photo for a larger version.

Thank you, Bob!

In addition to a clean dry wipe with a clean cloth... I've tried both 99% isp & wd40 specialist (no residue) contact cleaner to prep the surfaces.  Do you use the Cool Chem 310 activator with the adhesive?  If you do, do you apply the activator before or after applying the adhesive?

@Norton posted:

PLA is soluble in dicholomethane, aka methylene chloride. Micro Mark sells “ Same Stuff” which is or was Methylene Chloride.

Whatever they sell, it's not methylene chloride now - banned to the point where chemistry departments cannot afford the costs of meeting regulations.

When in doubt and for odd mixed materials, a little Goo on the joint, separate, add a little CA and back together.

@mwb posted:

Whatever they sell, it's not methylene chloride now - banned to the point where chemistry departments cannot afford the costs of meeting regulations.

When in doubt and for odd mixed materials, a little Goo on the joint, separate, add a little CA and back together.

It was originally methylene chloride as tested in our lab and the web page says its still MC. I have no means to test it now so can’t say for sure what it is. In any event a solvent cement will be an order of magnitude stronger than CA for this plastic. Save the CA for metal or dissimilar materials.

Pete

@Norton posted:

It was originally methylene chloride as tested in our lab and the web page says its still MC. I have no means to test it now so can’t say for sure what it is. In any event a solvent cement will be an order of magnitude stronger than CA for this plastic. Save the CA for metal or dissimilar materials.

Pete

Yes, it was originally and yes, correct on solvent cements!  But methylene chloride has been so beaten down this past year by really way over the top regulation and monitoring requirements that schools and labs in the country cannot meet that they are just stopping all use.  That hobby materials would have it in them...well, once upon a time asbestos was in use to make scenery.  We use MEK (great solvent cement for most plastics!) and it's got all kinds of respiratory issues as well as being very flammable.  CA, btw, is also not particularly safe stuff, yet we use it w/o giving safety a thought.....

I have no adhesive adhesion issues with PETG (Polyethylene terephthalate w/Glycol) at any size.  I intend to make all the parts available on OGR so it would be nice if the folks who use PLA have as easy of a go at it as possible.

Dennis, I use the activator after the integrator is applied.  They also make a primer product that I've never used.  All of the materials I've used are bonded well without it.

@mwb posted:

Yes, it was originally and yes, correct on solvent cements!  But methylene chloride has been so beaten down this past year by really way over the top regulation and monitoring requirements that schools and labs in the country cannot meet that they are just stopping all use.  That hobby materials would have it in them...well, once upon a time asbestos was in use to make scenery.  We use MEK (great solvent cement for most plastics!) and it's got all kinds of respiratory issues as well as being very flammable.  CA, btw, is also not particularly safe stuff, yet we use it w/o giving safety a thought.....

Maybe you could test some for us?? I know when the ban went into effect, retailers could still sell what they had in stock. I am thinking of aircraft paint stripper in particular.

Pete

I purchased a liter of methylene chloride on Amazon about a year ago and just checked whether it is still available -- it is. It is sold under the Uncliean America brand, a little pricy at $40, but available.

@CincinnatiWestern posted:

I purchased a liter of methylene chloride on Amazon about a year ago and just checked whether it is still available -- it is. It is sold under the Uncliean America brand, a little pricy at $40, but available.

The same amount of “Same Stuff” would be about 150 bucks so thats a deal.

Pete

@Bob posted:

Dennis, I use the activator after the integrator is applied.  They also make a primer product that I've never used.  All of the materials I've used are bonded well without it.

FWIW, I almost never use activator since I discovered some time back that water is an excellent activator.  I have read conflicting opinions on this, but the acid test is to try it yourself.  Just put the glue on one surface and moisten the other surface.  When brought together, they will bond almost instantly.  Baking soda is even faster, but a little harder to not make a bit of a mess.