Washing wood without warping


#1

I’ve picked through the forums and seen lots of people talking about cleaning wood post-engrave, but I haven’t seen anyone directly addressing the problem of warping after cleaning.

What I’ve taken from the forums: You should use alcohol, and of course, if you get wood too wet, it’s going to warp. I’ve heard someone say something about pumice? And others about rags and such.

But when you’re 3d engraving, say, PG maple, it’s gets pretty charred and sticky (even if you engrave without the masking) and the prints looks MUCH better when you scrub out some of the gunk with a toothbrush. I did a topographical print recently that just didn’t look good, so in the end, I decided ‘what the hell, it’s a waste anyhow, let’s scrub it and see what it looks like underneath’…and it looks FANTASTIC! Once all the canyons and river beds were cleaned out, ah man, the detail was stunning. But it wouldn’t have been possible without getting the wood “too wet”.

It got a bit worse before it was dry, too, despite my efforts - you could have wrapped that baby around a pipe. In the end, with a lot of coercion and a lot of glue, I managed to get it flat on another material, but the details are all rippled and broken and cracked, and the backside was rippled and splitting - I mean, it looks cool, but I guess what I am saying is…

…does anybody have the secret method for cleaning wood post-laser without warping the hell out of the wood?


Topographical 3D Engrave
#2

My best results were with alcohol and a toothbrush, quick rinse in water, blotted with a towel - followed by drying with compressed air and then under a quartz lamp for a few minutes.
The only engraves I have scrubbed clean with Fast Orange and a brush we’re deep engraves on 3/4" material. Water cleaning also results in a slightly raised grain.

After a heavy engrave I have had limited success running a low power pass to ‘clean’ it a bit.
I’m still new at this so I can’t help much.


#3

I’ve heard about this lower power pass for cleaning - anybody know more about that?

Alcohol, toothbrush, quick rinse with water was my exact process with the above pictures.


#4

Might try just alcohol and toothbrush but blot dry without a water rinse.


#5

I am getting excellent results by literally dousing with denatured alcohol. Not rubbing alcohol, denatured.

Then I wipe gently with a lint free rag while it’s still covered in liquid (work quickly, it evaporates sooner than you think), then rinse the entire thing with more alcohol. I gently pour it on the piece while it’s angled, rinsing slowly until the alcohol comes off relatively clear.

It sounds like a lot of work but It’s surprisingly fast.

Last, I blot with a paper towel — not rub, you’ll get paper stuck in the engrave if you do — and let air dry.

Results with Baltic birch:


1st 3D engrave project! Success!
#6

91% isopropyl alcohol in a spray bottle, and scrubbing with toothbrush has worked fine for me. No water rinsing, having the alcohol in a spray bottle lets you blast any remaining stuff loose.

Acetone also works.


#7

Having tried all three – 91% isopropyl, acetone (fingernail polish remover), and denatured, I am getting by far the best results with denatured alcohol. It’s not even close in terms of ease and overall result. No scrubbing is really necessary, just gentle wiping, and maybe not even that if you rinse enough. As such, you reduce the risk of damaging a delicate engrave. Isopropyl and fingernail polish both have a decent amount of water in them, I don’t think denatured has any.

Also, I use disposable gloves too. The pitch residue sticks to your hands like crazy and you’ll smell like an engraving all day if you don’t.

I will say, however, with all of these, work in a very well ventilated area with no fire sources nearby. All of these solvents will positively explode if you get a spark near their vapors. I work with the denatured stuff outside in the middle of the yard with a large plastic tupperware “basin”.

Stay safe, people!


#8

If the fingernail polish remover has water in it then you need to get a real container of acetone, there’s no water in that. Same for the alcohol, 91% is its concentration but regular “rubbing alcohol” is far less concentrated.


#9

I appreciate the denatured tip. I used isopropyl and got the above results.
Using it also required some solid scrubbing and enough liquid to rinse,
which again, yields the above results. I’m excited to too how denatured
works. Its probably safe to say that working with thicker material is also
a good idea.


#10

Hmm pure acetone is one I haven’t tried yet. I wonder which is more harmful, acetone or alcohol? Gut says acetone, but I don’t think breathing the vapors from either is going to be a healthy thing.

Anyone tried both and can offer a comparison?


#11

Unless you’re huffing increased concentrations of vapors or intentionally maintaining constant exposure to liquid solvents, neither is much to worry about in well ventilated conditions.

I use a lot of both 91% iso alcohol and acetone for cleaning engraves simply because I have a ton of acetone laying around for composites and I have a ton of 91% around for cleaning up resin for SLA 3D prints.

I wouldnt use acetone inside the house because the fumes are stronger however they evaporate/dissipate so quickly there’s less time for exposure than there is with alcohol.


#12

The spray bottle blast is a great idea.


#13

This might be a stupid question, but are you able to save/re-use your rinse DNA, or do you have to dispose of it after each use? Seems like that could get both very expensive, and very annoying (if your disposal regulations are anything like they are up here).


#14

Do you just let the isopropryl evaporate dry?

I just attempted to clean an engrave for the first time. I went the Fast Orange route, and ended up with some serious warping. Mind you, that might have been my technique. I was cleaning the brush with water quite frequently… not sure how liberal I should be with the Fast Orange, or the water (if any) with that method.


#15

Fast Orange can warp wood even if used without more water. Water is actually the first ingredient listed in its list of ingredients and apparently it’s enough to cause a problem.


#16

I know I opened the thread with one question, and am kinda of circumventing that question myself, but I thought it would be interesting to share my results after a couple days of experimenting.

I went and bought some denatured alcohol and did a few prints of the project I’m currently working on. I can’t post pictures before Christmas, but the 3d engraves I’m doing are topographical in nature. Since I’m using a full dynamic range of black-white in order to get a highly discernible landscape, I’m burning pretty deep into the wood and producing quite a bit of char.

Denatured alcohol, for my project, worked about as well as rubbing alcohol - it didn’t, really. Even when I included vigorous toothbrush scrubbing.

I kind of anticipated this, and also bought thicker wood - 1/4" BB ply made for laser burning, and the results on the wood were beautiful. So I was apprehensive when the DA didn’t work, because I knew I was gonna have to get in there with soap, water and a toothbrush, and was scared of warpage.

Long story short, dish soap, water and a toothbrush was by far the best result when cleaning off a deep burn like mine. You can’t argue with the amazing results @evansd2 is seeing with DA, but when the priority is to have a deep variable burn, the best option is to use thicker wood. The 1/4 unfinished BB showed only the most minuscule amount of warpage after fully-submerged scrubbing for several minutes.


#17

The DA takes on a lot of brown color. I’m not sure how you could reclaim it. I could be more efficient with it by getting a few pieces ready for cleaning and do them in a batch maybe, but it would require a bit of experimentation.

It also evaporates so quickly that it’s almost gone by the time you’re done. Have to think about this one.


#18

Got any pics? Sounds cool.


#19

Keep in mind that a plywood product is made of plies that have the grain oriented in alternating directions, so warping will be less problematic.

Solid woods will be a different story, and even then results will vary by species and their natural resistance to moisture.

You are right about the thickness too. More fiber/grain to resist against bending.


#20

Posted here: