Sometimes I want both > a great and smooth first layer plus a filament that does not really like to stick on that plate.
Then I found a way that provided an additional benefit and that’s what I would like to share today.
I needed some rather large parts and they had to be joined.
Most of the to be joined areas though I placed right onto the bed and with so really nothing to facilitate joining in the model.
Instead I used a sponge to create a really thin glue layer on the bed to then add a LIGHT and more misty coat of acrylic spray paint.
Just because I could I later added a slight mist of plastic primer as well.
After washing the glue off and letting it all properly dry I did the glue test…
PETG does not like many glues, hence the cheating.
So I had a brush and PVC primer/glue ready.
DO THIS OUTSIDE!
I used a tiny pump spray bottle that I filled with about 40ml of the MEK primer.
A quick spray on both parts and once touch dry I used the brush to add a thin layer of glue to one part - leaving a bit of a gap to the edge to allow the glue to spread out without making a huge mess.
One last quick spray on the other part and I left them clamped for about half an hour, followed by 24 hours to ensure the glue is set.
Good luck getting the parts separated…
It is a great cheat? Nope…
It is a perfect solution? Far from it…
But it is something worth to consider when all else seems to be too tricky or near impossible…
MEK is really bad stuff to get on your skin or in your eyes or to breath. I’d be really careful about putting it in a spray bottle and “spritzing” it, outdoors or not.
I don’t understand the process you used. If you had two PETG parts you wanted stuck together, MEK alone is more than sufficient. I just glued some PETG parts with MEK yesterday, in fact. Lined them up, clamped them together, then ran a little MEK with an applicator along the seam. A minute later they were stuck together as if they’d been printed that way.
Doing this is hardly a cheat. I do it all the time. Parts I can’t print “cleanly enough” get sliced in to smaller parts so I can orient the challenging areas more favorably. Stuck together afterwards, they’re as good as if they’d been printed that way. If necessary, I add “sacrificial” tabs to aid in alignment prior to gluing.
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Nice one.
I agree that MEK is nasty and also that it can solvent weld a lot of things.
PETG was only an example though 
There is a solvent for whatever need one might have - my chemistry teacher kept repeating this over and over again when organic chemistry was on the menu…
No surprise then that for basically all the plastics we might be able to print we CAN find a suitable solvent.
Does not mean though we can buy it legally, nor that we can use it without potential risks to our health or the environment.
Having said that…
I posted the above because the paint/primer bed abuse also works with those plastic you might not have a solvent for in you workshop - or where you don’t want to mess it the nasty stuff.
Like plastics that don’t really bond to each other and would require a special adhesive or resin based solution.
Also really helps if want to create a lasting bond to print directly onto things like leather or wood - just saying as I don’t advise trying with a Bambu printer.
In another thread I posted already how I found T-Rex sealant.
If I find a way to make those cartridges NOT to go hard so quick once opened I might use it as my preferred gluing option for prints.
Takes a while to fully cure, especially if it is a large area that only has a tiny seam around - but a little goes a long way with that stuff.
Not sure though if it is available outside Australia…