Hydrochloric acid etched glass as printbed?

Hi,

bed adhesion is still a bit of an issue for my printer. At the moment I have this sandwich of a silicon heater, followed by a 5mm alu plate that also keeps the bottom of my delta together, followed by a mirror to keep everything straight and topped of with a non-magnetic flex plate. It works but the flex plate is starting lift the corners up when heated. So I looked at magnetic plates which seem to be nice and I just saw a kickstarter for a prusa style PEI coated plate, but just looking at the fact that build tak charges upwards of 100$ for a decently sized plate, makes me not want to buy it.

I wondered then how i can reduce my sandwich to get more heat through all those layers and maybe even save myself from buying an expensive magnetic plate.
Long story short. I recently saw some glass etching in an antique shop and I can imagine that the etched surface would be good for the plastic to stick onto.
That would have the advantage of having a straight surface with hopefully better adhesion than polished glass.

No such thing as "Hydrochloric acid etched glass". this acid as is won't attack glass.
The acids used are quite nasty, better try with frosted glass or do it with abrasive.
I tried but not much difference and anyway gave up on glass.

Now it is PEI on an Al bed I can remove easily. For PETG I had to reduce the adhesion with rubbing alcohol.

Even more convenient, PEI on steel foil magnet as you saw. You find it too expensive so why not make it yourself ?

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"A comical prototype doesn't mean a dumb idea is possible" (Thunderf00t)

I suspect that sungod3k intended to say hydrofluoric acid which does etch glass. Glass beds acquire a very thin waxy coating that is not easily removed with solvents such as acetone or any of the usual cleaning methods - I think that this is similar to the road film found on car windscreens. The best I have found is distilled white vinegar as a final cleaning after rubbing with very fine wire wool.

Mike

The acid came up when i google glass etching together with sandblasting. Also frosted glass can be bought, but its also not that cheap. I wonder if one can belt sand a cheap mirror to get a consistently frosted effect.

As for PEI, we have some non prusa printers in our local fablab and i cant speak to the quality of their PEI beds, but the surface seems quite fragile. I like the robustness of the glass, not worrying about ripping into the surface etc.

As for the alu, my first printer had a 3mm alu bed and it would warp a lot while heated. I tried to help that with a thicker plate in my current printer, but its also not warp free it just takes longer, so Im not very confident using it without something in between like glass to get a straight surface.

I use PEI sheet from Banggood. Not expensive at all.
Al bed warping has been already discussed here many times. Fact is, a good Al bed can be made, it isn't rocket science neither very expensive.
Glass on a warped bed is an other source of problem.

Anyway, try frosted glass and let us know.

Edited 1 time(s). Last edit at 03/02/2019 03:36AM by MKSA.

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"A comical prototype doesn't mean a dumb idea is possible" (Thunderf00t)

Quote
leadinglights
Glass beds acquire a very thin waxy coating that is not easily removed with solvents such as acetone or any of the usual cleaning methods - I think that this is similar to the road film found on car windscreens. The best I have found is distilled white vinegar as a final cleaning after rubbing with very fine wire wool.

I find the secret is to scrub the glass thoroughly in clean water + washing up detergent, using a washing up sponge with a scouring pad on one face. Then rinse it and dry it with a paper towel. Don't use a dishcloth to dry it, because a dishcloth will probably have traces of fabric conditioner on it. Avoid finger marking the side you will print on. I too use a quick wipe with distilled vinegar (on a paper towel again) between prints.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

My strong preference with ABS is just clean glass without acetone slurry, hairspray, sugar solution or any of the propriatory products such as Wolfbite. The clean disconnect when the glass temperature drops below 65°C is a revelation after having curled edges with slurry, pulled out chunks of glass with Wolfbite etc.. The problem with glass is that ABS seems to poison the surface and only vinegar will revive it.

On frosting glass, in my youth we used to make frosted glass by rubbing two plates of glass together with wet VIM kitchen cleaning powder between them. I don't know if modern VIM is abrasive enough but may be worth a try.

Mike

Quote
sungod3k
So I looked at magnetic plates which seem to be nice and I just saw a kickstarter for a PEI coated plate, but just looking at the fact that build tak charges upwards of 100$ for a decently sized plate, makes me not want to buy it.

I am the creator of that Kickstarter and our prices include the shipping costs, even for international buyers (which is expensive). I think people don't realize that, because they see the 'high" reward cost and leave.

Edited 2 time(s). Last edit at 03/02/2019 02:19PM by klcjr89.

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klcjr89

Quote
sungod3k
So I looked at magnetic plates which seem to be nice and I just saw a kickstarter for a PEI coated plate, but just looking at the fact that build tak charges upwards of 100$ for a decently sized plate, makes me not want to buy it.

I am the creator of that Kickstarter and our prices include the shipping costs, even for international buyers (which is expensive). I think people don't realize that, because they see the 'high" reward cost and leave.

Indeed and it is why Chinese products cheap from the start get the added advantage of cheap if not 0 shipping cost thanks to state subsidies and Intl Post Office agreements that makes YOUR PO bear the cost of local shipping !

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"A comical prototype doesn't mean a dumb idea is possible" (Thunderf00t)