Favorite way to prep your bed surface for printing PLA?

Need some assistance getting started...post here...
User avatar
willnewton
Posts: 477
Joined: Wed Apr 09, 2014 8:32 pm

Favorite way to prep your bed surface for printing PLA?

Post by willnewton » Tue Apr 29, 2014 2:08 am

What is your current favorite way to ensure your bed is prepped for a good PLA print and what other techniques did you try before you got there? Most of the time, I slide a small putty knife or razor under the print or the tape layer, but this is what I have tried so far.

1. Bare glass: I clean the glass with denatured alcohol and get a shiny print, not always good for adhesion. Reusable with a quick cleaning.

2. WIDE blue painter's tape: After applying it to the bed, I give it a quick wipe with denatured alcohol, and get very good adhesion. Not always reusable, as it can tear or get TOO stuck to the the print. Leave a matte finish at best, or one that needs scraping/sanding to remove tape at worst.

3, 2 layers of blue tape. This is not bad. I leave a good layer down over the full bed and just slap on a small piece, sized for my print over that layer. I give it a wipe with den. alcohol and print. I can easily slide the knife in between and just remove the extra tape layer and 3dprint at one time. Then it is no problem to slap on some fresh tape, start the next print and I can deal with the tape while the next print is running. No improvement in finish.

But where to go next? What kind of prints do you get with glue stick? What about hairspray or runny Elmer's glue? Can you list a pros or cons? Do you keep multiple beds?
I'm finally back to where I started two days ago!

A thread with some stuff in it I update every once in a while. viewtopic.php?f=8&t=9
See some of my stuff http://www.thingiverse.com/willnewton/about

Dale Reed
Posts: 376
Joined: Thu Apr 10, 2014 1:39 am
Location: Cleveland Heights, Ohio USA

Re: Favorite way to prep your bed surface for printing PLA?

Post by Dale Reed » Tue Apr 29, 2014 3:53 am

willnewton,

I get the glass squeaky clean (as in your #1), then spray with Aqua Net unscented Extra Super Hold hair spray (when cold) -- a fine misting. Then I heat the bed, then another very fine mist of hair spray when it's hot. When that dries (almost instantly when the bed is at temp.), start printing.

I can do several prints in a session by scraping the bed clean with a razor blade, then heat up and apply another very fine mist of hair spray.

I try to always clean the glass squeaky clean at the end of the session --- but that's mostly so I can pose the printed part and take some photos!
Dale

markb
Posts: 180
Joined: Tue Apr 15, 2014 11:06 pm

Re: Favorite way to prep your bed surface for printing PLA?

Post by markb » Tue Apr 29, 2014 1:34 pm

I clean glass with denatured alcohol your #1
Heat the bed to 60C and print away.

jsc
Posts: 1864
Joined: Thu Apr 10, 2014 4:00 am

Re: Favorite way to prep your bed surface for printing PLA?

Post by jsc » Tue Apr 29, 2014 5:58 pm

Here's my experience:

1) Bare glass at 60-70C: worked fine for a few prints at the beginning, then started getting separation. A good cleaning restored stickiness, but it got to be too much of a hassle. You always have the worry that maybe on the next print it's not clean enough, should I clean it again now, etc. I didn't find cleaning with alcohol or acetone to improve matters much, I had to take the glass to the sink and wash it like a dish.

2) Painter's tape: works well, downsides as you list. Upsides are that it is quick to replace, and you don't have to heat the bed for PLA.

3) Hair spray: works. I had some broken down boxes in my den, so I'd place it on one of those and give it a spray down, then let it dry, give it another coat, repeat. I do not recommend you spray the glass on the bed because it is hard to control where the spray ends up. I no longer use hairspray because of the time it takes to apply, with all the waiting for drying, multiple coats, taking things on and off, and again I am subjected to the concern that maybe I should redo the prep for the next print. Some people apply non-aerosol hairspray in a squirt can with a roller, which seems like it would have the improved cycle time benefits as

4) Elmer's glue stick: best adhesion so far of the chemical treatments. For prints with a lot of bed contact, almost too good. You will need to do some prying at some point. You can weaken contact by wiping it around with a damp paper towel, but that can be a hit or miss affair: you don't want to remove the glue, just thin it out. I prefer to apply it full strength, then worry about removal later. I haven't had actual glass chipping yet. I try prying first, then freezing, then soaking. If you take the bed off the glass and look at the underside, it should be clear which parts are still adhered and you can work on those parts. This is just for PLA, mind you, for ABS it should be loose on the glass after print. Buy the 3 packs of large sticks over the 6 packs of small glue sticks, you get more glue for less money by weight and it's easier to apply.

5) Diluted white glue: this seems better in that you can control the strength of adhesion more directly. I have not tried it yet because of storage issues: you need a jar, and a brush, and ideally some way to keep the brush in the jar without letting the contents dry out.

Toby
Posts: 330
Joined: Wed Apr 09, 2014 9:44 pm

Re: Favorite way to prep your bed surface for printing PLA?

Post by Toby » Tue Apr 29, 2014 6:14 pm

jsc wrote: 5) Diluted white glue: this seems better in that you can control the strength of adhesion more directly. I have not tried it yet because of storage issues: you need a jar, and a brush, and ideally some way to keep the brush in the jar without letting the contents dry out.
I've just been using a small plastic container and an artist style paint brush. The brush can be rinsed out after each application, but you're right it is a bit of a pain and it would be better to store the brush in the container.

I remember as a kid we had these "glue pots" in school which had a brush built into the metal twist-on top. I wonder if they still make anything like that.

Edit: Well come to think of it, I wonder if we can make anything like that. Of course we can.

User avatar
willnewton
Posts: 477
Joined: Wed Apr 09, 2014 8:32 pm

Re: Favorite way to prep your bed surface for printing PLA?

Post by willnewton » Tue Apr 29, 2014 7:56 pm

As far as the hairspray, glue stick, and glue goes, what kind of finish does it leave on the print? I would assume it is a bit matte.
I'm finally back to where I started two days ago!

A thread with some stuff in it I update every once in a while. viewtopic.php?f=8&t=9
See some of my stuff http://www.thingiverse.com/willnewton/about

jsc
Posts: 1864
Joined: Thu Apr 10, 2014 4:00 am

Re: Favorite way to prep your bed surface for printing PLA?

Post by jsc » Tue Apr 29, 2014 7:58 pm

It leaves a smooth surface, as on bare glass.

jbarnhardt
Posts: 27
Joined: Wed Apr 09, 2014 10:56 pm
Location: Seattle, WA

Re: Favorite way to prep your bed surface for printing PLA?

Post by jbarnhardt » Tue Apr 29, 2014 8:59 pm

I've tried most of these methods as well (bare glass, painter's tape, glue stick, hairspray) and would agree with the very set of pros/cons that you stated in the introductory post for glass and tape. I found like Jin that glass by itself was a little more of a crapshoot - it occasionally wouldn't stick well and it was hard to tell for sure if you were going to succeed. Glue stick (Elmer's purple) worked pretty well and is easy to apply, but can be a little messy/gloopy in application. FWIW I never had prints that were hard to remove using glue stick, but I tend to print items that are 5" or less in any dimension so perhaps that's the reason (less surface for adhesion). I started using hair spray (Aquanet Super Extra Hold, normal spray can) and that is my favorite solution at this point. Pull the glass, spray it lightly, replace and let dry (<5min) and I can print 3-5 objects with good adhesion before needing to spray again. A 2nd (or 3rd) coat can be applied if you want to increase stickiness, but so far a single coat has worked for me for PLA. I did use a double coat on Kapton for an ABS print the other day (rsilver's M2 hot end mount) that kept wanting to pull up in the corners, and that worked pretty well. So at this point my preference is for hair spray as I find it quick, easy and effective. But perhaps the best takeaway is that pretty much all of these methods work pretty well so you have a lot of freedom to choose the one(s) that work best for your printing workflow.

-John

P.S. Will, I recognize your avatar from the DLG threads over on RCGroups... Nice to see you here.

User avatar
willnewton
Posts: 477
Joined: Wed Apr 09, 2014 8:32 pm

Re: Favorite way to prep your bed surface for printing PLA?

Post by willnewton » Wed Apr 30, 2014 8:38 pm

jbarnhardt wrote:P.S. Will, I recognize your avatar from the DLG threads over on RCGroups... Nice to see you here.
Haha, yep that's me! I haven't messed around over there for a while (especially DLG, since I herniated two discs in my back). I still keep a small quadcopter around for playing. Man, if I had one of these printers while I was hot into R/C, it would've been a lot of fun.
I'm finally back to where I started two days ago!

A thread with some stuff in it I update every once in a while. viewtopic.php?f=8&t=9
See some of my stuff http://www.thingiverse.com/willnewton/about

jsc
Posts: 1864
Joined: Thu Apr 10, 2014 4:00 am

Re: Favorite way to prep your bed surface for printing PLA?

Post by jsc » Wed Apr 30, 2014 9:16 pm

Had to look up DLG. Is anyone doing 3D printed gliders? Balsa wood seems to have a density of 10-15% that of ABS, so perhaps a 15% infill print might be workable.

Post Reply