Blasting cabinet haze prevention

[drummerdimitri]

How do you guys deal with hazing of your blasting cabinet's viewing window?

I currently have a 6mm thick tempered glass as my main panel but I stuck a plastic protection film to prevent the glass from fogging up.

The problem though is I need to change it every hour of blasting and that's not a convenient thing to do.

I haven't tried blasting with no protection at all as I am not sure how long it would take for the tempered glass to haze and that costs 50$ to replace.

Would having an air curtain blasting across the glass reduce the particles hitting it?

I could also use acrylic sacrificial sheets 1-2 mm thick but I'm not sure those will last longer than the plastic film I am currently using.

Maybe regular glass would be the best way to go and just have it changed when it eventually hazes up as it would be cheaper than the tempered variant.

What has worked for you so far?

 

[moemc]

How many hours per season do you think you use the cabinet? For comparison, I use my cabinet around 12 hours steady per batch of parts, every 3 months or so. I use glass bead at much higher than recommended pressure. I use a carbide nozzle that is way too big, and I have a screw compressor that is able to keep up continuously.

No plastic sheet protector on the glass for 5-6 years. The plastic covers were annoying, as you are experiencing. My window is only barely hazed, and at this pace, I dont know if I will replace it ever unless there is a mishap. But if this was being used every single day in a full-on mass production environment, the window might need replacement regularly.

I might suggest trying a semi-direct hit to an unprotected area to see how your window responds? But I expect a more aggressive media than glass bead can probably chew up the windows pretty quick. Let me see if I can find on the website what my window is made from. EDIT: It is advertised as having a tempered glass window.

 

[gregs]

I have plain glass that I get cut at Lowe’s. I added a wood frame in front of it covered with screen wire. That seems to help.

 

[GeoBruin]

Tacoma quick change glass kit and cheap glass from home depot. You can cut the glass yourself with a 5 dollar glass cutter so you buy one sheet and you can get 2 or 3 pieces out of it. Lasts way longer than the plastic sheets.

 

[American Locomotive]

I think it really depends on what media you use. I put aluminum oxide in my cabinet, and it beat up the glass fast. They make "tear off" plastic films for blast cabinets. It's like a stack of 10 plastic sheets stuck together with easy pull tabs. You just pull off one layer at a time as it gets beat up.

 

[engineer2]

Under the glass I had a sheet of acrylic and then window screen all separated about 1/4". Seems to work OK. If the acrylic gets hazy, I'll replace it. I don't do a lot of sandblasting, so it's going to last a while.

 

[drummerdimitri]

I usually blast for about an hour daily to remove mill scale off of my cnc plasma cut parts prior to welding and/or powder coating.

The media I use is iron silicate AKA copper slag with grain sizes ranging from 0.2 to 1 mm so quite coarse media.

It is more abrasive than glass bead and I blast initially at high pressure 100 psi but that drops down and stabilizes at around 60 psi as I use a 15 HP airjet on my 10 HP screw compressor.

I just might have to try blasting without the plastic protection screen to see how long my glass will last. If it is 6 months or more than I'd be happy to treat it as a sacrificial piece, otherwise I will have to find other methods that last a decent amount and don't cost a ton.

The screen idea is interesting. Will a plastic mosquito net type work?

 

[MileHighRover]

My Snap-on cabinet uses a fine mesh metal screen in front of the glass. Seems to work as the cabinet is old and the glass has never been replaced.

 

[rlitman]

...The screen idea is interesting. Will a plastic mosquito net type work?

Yes, exactly. The coarser the media the better it works. I would suggest having it a bit loose.

For my sandblaster (which I also only use a few hours a year), I use the leftover glass smartphone screen protectors that I've accumulated as I've upgraded phones.

 

[gregs]

I used regular metal (aluminum I think) window screen.

 

[drummerdimitri]

I used regular metal (aluminum I think) window screen.

Do you have X-ray vision mate? How do you see through it?

 

[gregs]

Do you have X-ray vision mate? How do you see through it?

I guess I do. The same way I can see out of a screen window or door.....??

 

[drummerdimitri]

My Snap-on cabinet uses a fine mesh metal screen in front of the glass. Seems to work as the cabinet is old and the glass has never been replaced.

Do you mind sharing a picture of what that looks like? I'm curious to see how they've implemented this idea.

 

[gregs]

Do you mind sharing a picture of what that looks like? I'm curious to see how they've implemented this idea.

I dont, but Google does....

 

[Jeff Ivers]

I give a couple of squirts of Windex to a paper towel, open the cabinet, and wipe both the underside of the window and light. I do this after about every hour of blasting. Eventually the acrylic covering my glass will get discolored to the point that I remove the window and apply a fresh sheet of acrylic. The best acrylic I have found is to go to the hobby/sewing shop and purchase clear vinyl tablecloth from a roll.

 

[driftpin]

From Feb. 2, 2024:

Stainless screen, very fine, does a good job of saving the glass.

HF Blast Cabinet Skat Pick Up Tube vs Manifold vs Reclaimer

I have a harbor freight blast cabinet that I've done all the basic mods on including swapping out to a Skat gun and pickup tube which works a million times better than the original HF gun and pick up tube. I currently have my fresh air coming in off the back and my exhaust to my dust devil...

www.garagejournal.com

I haven't had to replace the glass since this mod.

 

[Steve_P]

I use the plastic sheets. I try to hold the part so that the media deflects away from the window. They're consumable and it is what it is.

 

[BillK]

I just changed the 1/4" tempered glass in the blaster at my business. Its probably been at least 7-8 years. I use glass beads only. The key is to not blast anywhere towards the glass lol. My cabinet is pretty big so its not a big issue.

 

[rsanter]

I built my blast cabinet years 35 years ago. Used the hell out of it back in the day but don’t use it much anymore. The plan is to convert it to a vapor hone cabinet.
at any rate, I was trying to use as much material I had on hand as I could so I used a piece of lexan that I had for the large viewing window I wanted. Then I used a piece of window screen in an aluminum frame (I grabbed it off the side of street pickup pile) thinking I didn’t have much to loose.

after all these years I am still using the original piece of lexan for the viewing window.

 

[MileHighRover]

Do you mind sharing a picture of what that looks like? I'm curious to see how they've implemented this idea.

Here you go. It's just attached with fasteners through the lid. I included a picture looking through the glass. The screen doesn't affect the view. It's a tight mesh, too. Way smaller holes than a window screen.

 

[Jeff Ivers]

I usually blast for about an hour daily to remove mill scale off of my cnc plasma cut parts prior to welding and/or powder coating.

The media I use is iron silicate AKA copper slag with grain sizes ranging from 0.2 to 1 mm so quite coarse media.

It is more abrasive than glass bead and I blast initially at high pressure 100 psi but that drops down and stabilizes at around 60 psi as I use a 15 HP airjet on my 10 HP screw compressor.

I just might have to try blasting without the plastic protection screen to see how long my glass will last. If it is 6 months or more than I'd be happy to treat it as a sacrificial piece, otherwise I will have to find other methods that last a decent amount and don't cost a ton.

The screen idea is interesting. Will a plastic mosquito net type work?

I see most on here are replying to your original post with proposed solutions to keep your window from being etched which reduces visibility. I have found that any kind of blasting generates very fine dust particles of rust , paint, etc which will settle on the bottom of the viewing window and on whatever protects your light (if in the cabinet). Perhaps my experience is due to static electricity making those particles cling to the window and others don't experience that. I have a piece of vinyl protecting the bottom of my window and it has been in place for over a year. I find it hard to believe that if you have plastic on the bottom of your window it is getting etched that fast. Is your problem etching or accumulated dirt particles? Have you tried cleaning instead of replacing?

 

[rslaback]

I upgraded the media blaster at work to use these mylar rolls. It isn't perfect but it beats the individual sheets we used before this.

 

[TonyG109]

I also use the window screen trick. But being lazy, I just used magnets to hold the screen in place. Cut the screen big so it overlaps the window by a few inches and apply several strong magnets. Quick and painless.

 

[MileHighRover]

I also use the window screen trick. But being lazy, I just used magnets to hold the screen in place. Cut the screen big so it overlaps the window by a few inches and apply several strong magnets. Quick and painless.

Excellent tip! So smart yet so simple.

 

[rlitman]

I also use the window screen trick. But being lazy, I just used magnets to hold the screen in place. Cut the screen big so it overlaps the window by a few inches and apply several strong magnets. Quick and painless.

I am SO doing this before I blast next (if I remember). One thing I'll do though is add two strips of stick on foam weatherstrip above and below the window, so the screen is suspended a fraction of an inch away from it.

 

[TonyG109]

I am SO doing this before I blast next (if I remember). One thing I'll do though is add two strips of stick on foam weatherstrip above and below the window, so the screen is suspended a fraction of an inch away from it.

That's a great idea. Mine is a bit loose so it naturally hangs about an inch below the glass. It tweaks the OCD but I learned to live with it!

 

[TonyG109]

If you use window screen across the glass, it seems to help to use a dark screen as opposed to a silver colored screen. I find it easier to "see through" the dark screen. It may also help to turn out the lights outside/above the blast cabinet. The prevents the side of the screen that faces you from being lit up which makes the screen less visible and easier to see through.

 

[MileHighRover]

I am SO doing this before I blast next (if I remember). One thing I'll do though is add two strips of stick on foam weatherstrip above and below the window, so the screen is suspended a fraction of an inch away from it.

You could do the same by placing a magnet on the lid, then the screen, then another magnet. The extra magnet will be your spacer. Would hold up better than a piece of foam.