Acryic and Denatured Alcohol?
Posted: Tue Mar 05, 2019
Post by Mike Audleman » Sun May 14, 2017 6:09 pm
Ok. Is this a known that I have simply missed entirely or something new I have found?
I was cutting some little dolphins out for the O/L. I had a shaded portion (scan) on it prior to the cut to give it a different look (belly). After cutting a couple out I noticed fractures all over in the etched area and along the edges. I looked at them funny and was doing a WTH? So I grab another chunk of acrylic and try a couple there. Same thing.
So I grab a third piece and scale the file up thinking maybe its just too small a part (30mm roughly). Up it to 50. Cut one. It looks ok. So I grab my paper towel that I have been wiping them with and before my eyes it crackels! Its not happening in the laser! So I wipe an area thats devoid of cracks and slowly they begin to appear. I dampen the towel with fresh alcohol and wipe another area and they appear more quickly. So its the alcohol!
I cut another 50mm one and this time I head for the cold water in the sink, maybe its heat and cold. Nope no cracks what so ever. Clean. I wipe it with the towel and there the cracks form. Definitely the alcohol.
Its 100%. Every one I have NOT wiped with alcohol has no cracks. Every one I HAVE wiped with alcohol has cracks. Its not maybe. Its every single one.
Has anyone else run across this? I somehow doubt its this specific file or this specific shape or these specific settings. The etch is not very deep, 250mm/s at 25% isn't much. Just enough to get through the protective sheet and just a pinch into the surface for a bit of texture so its not even a real deep etch like one would do for a photo or 3D carving.
The specific material is .220 Acrylic 18x24 sheets from Menards. Its the only acrylic I have at the moment so I can't try another brand.
https://www.menards.com/main/building-m ... 882878.htm
The alcohol is from Home Depot:
http://www.homedepot.com/p/Klean-Strip- ... /100118908
----------------
Post by Malcolm Ferrie » Sun May 14, 2017 7:09 pm
Can you post a photo of the problem, It sounds like you are cutting it too slowly
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Post by John Lifer » Sun May 14, 2017 7:28 pm
No, denatured alcohol can and in your case has damaged your acrylic. Nothing new here! Alcohol of any sort can craze acrylic
--------------------
Post by Mike Audleman » Mon May 15, 2017 9:18 am
If alcohol isn't a proper choice, then what do yall clean your parts with?
-----------------------
Post by Gene Uselman » Mon May 15, 2017 9:51 am
Here is a sample of IP alcohol after cut/engraving- we use IPA to clean everything and it has been a problem getting people to think before they clean.
I use a adhesive remover mostly [Rapid Remover] which is a citrus type remover. Gene -----------------------
Post by Mike Audleman » Mon May 15, 2017 10:29 am
The ones along the outside edge are exactly what I am seeing. However I am not getting the long lateral lines in the etch area. Mine are a crackling, sorta smashed windshield look. Unfortunately I pitched them in the trash (and took the trash out per O/L request). I can do another cut and throw some alcohol on it to recreate the issue so I can photograph it.
In any event, I didn't ruin any big projects. Only tiny bobbles I was cutting out just for play than anything. I wasn't using IPA either, it was DA. But I guess the fundamental element there was alcohol. Apparently its a bad combo with acrylic. It does a stand up job on burn residue on cut ply and doesn't raise the grain like IPA which is cut with water or other water based cleaners.
I have couple different citrus cleaners around somewhere. I will have to do some more etchings on scraps and test those
---------------------------
Post by Gene Uselman » Mon May 15, 2017 11:29 am
I have never had a problem with Denatured alc, I have used it to take off old paper coverings from acrylic .
-------------------
Is that the plastic protective coating that is doing it?
------------------
Post by Gene Uselman » Mon May 15, 2017 12:41 pm
Nope- I removed it and replaced with paper premask- this is after removing the paper mask and cleaning up for delivery. I toldja I had a hella time with this 30" edgelit. That was not a good day. Gene
----------------------
Post by Leo Voisine » Mon May 15, 2017 5:07 pm
Just a thing to note about Denatured Alcohol.
It is NOT all the same.
It USED to be Ethanol, back in the day. That's the stuff in booze that gets you drunk. Ethanol that is treated to make you sick if you drink it is called Denatured alcohol. At least it used to be that way. Ethanol is actually a somewhat "healthy" product. Ethanol is a natural product derived from corn and the like. It is user friendly to your skin.
BUT - the stuff you get today called Denatured alcohol contains Methanol. That stuff is REALLY BAD stuff. Methanol is a petroleum byproduct. If drank even small quantities can kill you - fast. It is bad on the skin and in no way to be considered "healthy".
Parks, in the green can has the highest quantity of Ethanol I can find, I think 80% ETHANOL. Others can be as much as 70% METHANOL.
Even though they "sound" the same - METHANOL (bad stuff) is NOT the same as ETHANOL (good stuff).
After I run out of the BAD DNA, I am going to switch to the Parks Green can stuff.
Plastic is a petroleum by product. Methanol is a petroleum by product.
ETHANOL - is NOT a petroleum byproduct.
So - I just wonder if real ETHANOL would cause the same issue on the plastic.
I don't know where to find 100% Ethanol DNA.
I would like to know.
There is a LOT more that can be said about the differences, but that is another story.
----------------------
Post by Kevin Johnson » Mon May 15, 2017 6:29 pm
Call be picky, but --
Methanol, also known as "wood alcohol", was once produced as a byproduct of the distillation of wood. Today, methanol is produced in a catalytic process directly from carbon monoxide, carbon dioxide, and hydrogen. (not exactly petroleum) It IS and always has been poisonous. Prior to the use of ethanol in gasoline, most denatured alcohol was ethanol treated with copper sulfate, the copper sulfate added to make it 1) disgusting tasting, and 2) poisonous. Now days, DNA is a blend of ethyl and methyl. The SDS for Klean-Strip - Mike's link - shows its a ~ 50-50 blend.
---------------------
Post by Doug Fisher » Tue May 16, 2017 12:52 am
Isn't the effect of alcohol different on extruded acrylic versus cast acrylic?
-------------------
Post by Mike Audleman » Tue May 16, 2017 10:09 am
Well. Mostly right anyway.
Methanol is toxic. Highly toxic in fact.
DNA did used to be mostly ethanol and contained toxic substances to denature or de naturalize it against human consumption. Not sure if this actually changed or not. Haven't looked at a can recently.
However, Methanol is not a petroleum byproduct. A byproduct is a product produced as an ancillary product from producing a main product. I.E. Bone meal is a byproduct of the meat industry. We don't raise cattle for bones. We raise it for meat. The bones are an ancillary product. Methanol is not a byproduct, its a primary product produced on purpose. While it can be produced from a lot of sources, right now, the cheapest and easiest is natural gas as a source material, or more specifically methane gas (which can be either naturally occurring or produced from a methane digestor using manure and other byproducts of farming as sources).
And here is the twist you didn't expect. Ethanol, the "healthy" alcohol, IS actually a petrochemical byproduct! However that is not its main source for economical and political reasons. Fermentation of sugary sources (corn mainly) is its chief source however the only reason for that is the farm subsidies being provided by the government. Otherwise, it would mainly be produced from petroleum hydration during the production of ethylene which, without the subsidies, would be a cheaper method of production. And, yea, its whats in drinkin' stuff like wine, beer, tequila, bourbon, etc. as supplied by fermentation of sugars.
And...here is the other twist you didn't expect. Methanol IS what was (and currently is mostly) used to "denature" DNA :) Ethanol plus methanol IS DNA! IPA and MEK also get used from time to time depending on the company formula as well as other chemicals to bitter it. Google "methylated spirits" :)
Leo Voisine wrote: ↑
Mon May 15, 2017 5:07 pm
So - I just wonder if real ETHANOL would cause the same issue on the plastic.
I don't know where to find 100% Ethanol DNA.
I would like to know. Go to the liquor store and buy Everclear. Pour in a couple caps of Methanol. Poof. DNA. Unless you are in Bolivia get Cocoroco or in Poland grab a bottle of Spirytus Stawski. Those are the only consumer obtainable sources for any purer ethanol than Everclear that I know of. Don't think either is commonly available here in the US but you might be able to special order them. Or, you could simply skip adding the methanol or MEK and just keep a bottle of Everclear on the bench. As long as your kids don't find it :mrgreen:
-----------------------------
Post by sebastien laforet » Wed May 17, 2017 3:44 am
when cleaning perspex, i use isopropyl alcohol at 99% concentration, and it works nicely. i bought this stuff primarily for cleaning mirrors and lens (following the seller's doc). never got a crack on perspex and it's fine for removing dust from engraving.
it was somewhat difficult to find (not available in hardware stores), but the high concentration guarantees there will be no residue when the alcohol dries (that is important for mirror/lens cleaning).
whatever, this stuff is not very good at removing burn marks on the steel plate... probably not aggressive enough, acetone would be better.
---------------
Post by Kevin Johnson » Wed May 17, 2017 11:47 am
When I first read Mike's post, I thought it might have something to do with there being more than 1 type of material labeled "acrylic". I don't have any cast acrylic on hand, but had the cast versus extruded thought as well - maybe the extrusion process is stressing the surface?
----------------------
Post by Mike Audleman » Wed May 17, 2017 1:07 pm
I am unsure whether this it cast or extruded since there is no indication on their website nor Menards' site either. Its the only acrylic I have right now
----------------------
Ok. Is this a known that I have simply missed entirely or something new I have found?
I was cutting some little dolphins out for the O/L. I had a shaded portion (scan) on it prior to the cut to give it a different look (belly). After cutting a couple out I noticed fractures all over in the etched area and along the edges. I looked at them funny and was doing a WTH? So I grab another chunk of acrylic and try a couple there. Same thing.
So I grab a third piece and scale the file up thinking maybe its just too small a part (30mm roughly). Up it to 50. Cut one. It looks ok. So I grab my paper towel that I have been wiping them with and before my eyes it crackels! Its not happening in the laser! So I wipe an area thats devoid of cracks and slowly they begin to appear. I dampen the towel with fresh alcohol and wipe another area and they appear more quickly. So its the alcohol!
I cut another 50mm one and this time I head for the cold water in the sink, maybe its heat and cold. Nope no cracks what so ever. Clean. I wipe it with the towel and there the cracks form. Definitely the alcohol.
Its 100%. Every one I have NOT wiped with alcohol has no cracks. Every one I HAVE wiped with alcohol has cracks. Its not maybe. Its every single one.
Has anyone else run across this? I somehow doubt its this specific file or this specific shape or these specific settings. The etch is not very deep, 250mm/s at 25% isn't much. Just enough to get through the protective sheet and just a pinch into the surface for a bit of texture so its not even a real deep etch like one would do for a photo or 3D carving.
The specific material is .220 Acrylic 18x24 sheets from Menards. Its the only acrylic I have at the moment so I can't try another brand.
https://www.menards.com/main/building-m ... 882878.htm
The alcohol is from Home Depot:
http://www.homedepot.com/p/Klean-Strip- ... /100118908
----------------
Post by Malcolm Ferrie » Sun May 14, 2017 7:09 pm
Can you post a photo of the problem, It sounds like you are cutting it too slowly
----------------------
Post by John Lifer » Sun May 14, 2017 7:28 pm
No, denatured alcohol can and in your case has damaged your acrylic. Nothing new here! Alcohol of any sort can craze acrylic
--------------------
Post by Mike Audleman » Mon May 15, 2017 9:18 am
If alcohol isn't a proper choice, then what do yall clean your parts with?
-----------------------
Post by Gene Uselman » Mon May 15, 2017 9:51 am
Here is a sample of IP alcohol after cut/engraving- we use IPA to clean everything and it has been a problem getting people to think before they clean.
I use a adhesive remover mostly [Rapid Remover] which is a citrus type remover. Gene -----------------------
Post by Mike Audleman » Mon May 15, 2017 10:29 am
The ones along the outside edge are exactly what I am seeing. However I am not getting the long lateral lines in the etch area. Mine are a crackling, sorta smashed windshield look. Unfortunately I pitched them in the trash (and took the trash out per O/L request). I can do another cut and throw some alcohol on it to recreate the issue so I can photograph it.
In any event, I didn't ruin any big projects. Only tiny bobbles I was cutting out just for play than anything. I wasn't using IPA either, it was DA. But I guess the fundamental element there was alcohol. Apparently its a bad combo with acrylic. It does a stand up job on burn residue on cut ply and doesn't raise the grain like IPA which is cut with water or other water based cleaners.
I have couple different citrus cleaners around somewhere. I will have to do some more etchings on scraps and test those
---------------------------
Post by Gene Uselman » Mon May 15, 2017 11:29 am
I have never had a problem with Denatured alc, I have used it to take off old paper coverings from acrylic .
-------------------
Is that the plastic protective coating that is doing it?
------------------
Post by Gene Uselman » Mon May 15, 2017 12:41 pm
Nope- I removed it and replaced with paper premask- this is after removing the paper mask and cleaning up for delivery. I toldja I had a hella time with this 30" edgelit. That was not a good day. Gene
----------------------
Post by Leo Voisine » Mon May 15, 2017 5:07 pm
Just a thing to note about Denatured Alcohol.
It is NOT all the same.
It USED to be Ethanol, back in the day. That's the stuff in booze that gets you drunk. Ethanol that is treated to make you sick if you drink it is called Denatured alcohol. At least it used to be that way. Ethanol is actually a somewhat "healthy" product. Ethanol is a natural product derived from corn and the like. It is user friendly to your skin.
BUT - the stuff you get today called Denatured alcohol contains Methanol. That stuff is REALLY BAD stuff. Methanol is a petroleum byproduct. If drank even small quantities can kill you - fast. It is bad on the skin and in no way to be considered "healthy".
Parks, in the green can has the highest quantity of Ethanol I can find, I think 80% ETHANOL. Others can be as much as 70% METHANOL.
Even though they "sound" the same - METHANOL (bad stuff) is NOT the same as ETHANOL (good stuff).
After I run out of the BAD DNA, I am going to switch to the Parks Green can stuff.
Plastic is a petroleum by product. Methanol is a petroleum by product.
ETHANOL - is NOT a petroleum byproduct.
So - I just wonder if real ETHANOL would cause the same issue on the plastic.
I don't know where to find 100% Ethanol DNA.
I would like to know.
There is a LOT more that can be said about the differences, but that is another story.
----------------------
Post by Kevin Johnson » Mon May 15, 2017 6:29 pm
Call be picky, but --
Methanol, also known as "wood alcohol", was once produced as a byproduct of the distillation of wood. Today, methanol is produced in a catalytic process directly from carbon monoxide, carbon dioxide, and hydrogen. (not exactly petroleum) It IS and always has been poisonous. Prior to the use of ethanol in gasoline, most denatured alcohol was ethanol treated with copper sulfate, the copper sulfate added to make it 1) disgusting tasting, and 2) poisonous. Now days, DNA is a blend of ethyl and methyl. The SDS for Klean-Strip - Mike's link - shows its a ~ 50-50 blend.
---------------------
Post by Doug Fisher » Tue May 16, 2017 12:52 am
Isn't the effect of alcohol different on extruded acrylic versus cast acrylic?
-------------------
Post by Mike Audleman » Tue May 16, 2017 10:09 am
Well. Mostly right anyway.
Methanol is toxic. Highly toxic in fact.
DNA did used to be mostly ethanol and contained toxic substances to denature or de naturalize it against human consumption. Not sure if this actually changed or not. Haven't looked at a can recently.
However, Methanol is not a petroleum byproduct. A byproduct is a product produced as an ancillary product from producing a main product. I.E. Bone meal is a byproduct of the meat industry. We don't raise cattle for bones. We raise it for meat. The bones are an ancillary product. Methanol is not a byproduct, its a primary product produced on purpose. While it can be produced from a lot of sources, right now, the cheapest and easiest is natural gas as a source material, or more specifically methane gas (which can be either naturally occurring or produced from a methane digestor using manure and other byproducts of farming as sources).
And here is the twist you didn't expect. Ethanol, the "healthy" alcohol, IS actually a petrochemical byproduct! However that is not its main source for economical and political reasons. Fermentation of sugary sources (corn mainly) is its chief source however the only reason for that is the farm subsidies being provided by the government. Otherwise, it would mainly be produced from petroleum hydration during the production of ethylene which, without the subsidies, would be a cheaper method of production. And, yea, its whats in drinkin' stuff like wine, beer, tequila, bourbon, etc. as supplied by fermentation of sugars.
And...here is the other twist you didn't expect. Methanol IS what was (and currently is mostly) used to "denature" DNA :) Ethanol plus methanol IS DNA! IPA and MEK also get used from time to time depending on the company formula as well as other chemicals to bitter it. Google "methylated spirits" :)
Leo Voisine wrote: ↑
Mon May 15, 2017 5:07 pm
So - I just wonder if real ETHANOL would cause the same issue on the plastic.
I don't know where to find 100% Ethanol DNA.
I would like to know. Go to the liquor store and buy Everclear. Pour in a couple caps of Methanol. Poof. DNA. Unless you are in Bolivia get Cocoroco or in Poland grab a bottle of Spirytus Stawski. Those are the only consumer obtainable sources for any purer ethanol than Everclear that I know of. Don't think either is commonly available here in the US but you might be able to special order them. Or, you could simply skip adding the methanol or MEK and just keep a bottle of Everclear on the bench. As long as your kids don't find it :mrgreen:
-----------------------------
Post by sebastien laforet » Wed May 17, 2017 3:44 am
when cleaning perspex, i use isopropyl alcohol at 99% concentration, and it works nicely. i bought this stuff primarily for cleaning mirrors and lens (following the seller's doc). never got a crack on perspex and it's fine for removing dust from engraving.
it was somewhat difficult to find (not available in hardware stores), but the high concentration guarantees there will be no residue when the alcohol dries (that is important for mirror/lens cleaning).
whatever, this stuff is not very good at removing burn marks on the steel plate... probably not aggressive enough, acetone would be better.
---------------
Post by Kevin Johnson » Wed May 17, 2017 11:47 am
When I first read Mike's post, I thought it might have something to do with there being more than 1 type of material labeled "acrylic". I don't have any cast acrylic on hand, but had the cast versus extruded thought as well - maybe the extrusion process is stressing the surface?
----------------------
Post by Mike Audleman » Wed May 17, 2017 1:07 pm
I am unsure whether this it cast or extruded since there is no indication on their website nor Menards' site either. Its the only acrylic I have right now
----------------------