Hi guys. I have a few questions about this job, in which I have to blast 2.25" from the top edge of these tiny, 17' tall glass windows. The purpose of this is to hide where the glass meets the cement, which looks kinda cruddy. Its a total of 60 panels, & each will need 58-60" x 2.25" of sandblasted area. I've never taken on a project like this, which really doesn't seem to be too complicated, but I just want to do it right. I guess my questions start with: How much can I get for this job, & how do I go about it, without making a mess of the place? Any help will be truly appreciated.
Thanks always, Felix
Here are the photos:
Posted by mike meyer (Member # 542) on :
just take a hammer to it and break all that glass outta there....it don't snow there anyway...
Posted by Wayne Webb (Member # 1124) on :
Felix, Just looking at it, I wouldn't knwo how much time it would require. So, I would do it by the hour. You would need to mask all of the window surfaces to protect them from the blast. Seems to me you would need to cover that stucco too. It wouldn't take alot of blasting to frost that glass so there shouldn't be much mess I would think
[ March 17, 2008, 09:49 AM: Message edited by: Wayne Webb ]
Posted by Felix Marcano (Member # 1833) on :
What should we use to mask off such a large piece of glass? Blast mask would surely be expensive. Or should I just use blast mask only where I'll be blasting, & transfer tape on the rest? Or is there something I don't know about? Something I could roll on, perhaps?
[ March 17, 2008, 09:53 AM: Message edited by: Felix Marcano ]
Posted by Kelly Thorson (Member # 2958) on :
Felix, if you are just frosting it you should be fine with 3 mil vinyl. You could tape poly over most of the area or use transfer tape. Just make sure you have masked any of the area that you will be blasting near with vinyl or sandblast mask. That looks like you are in a giant clam or oyster shell...is that what it is supposed to look like?
Posted by mike meyer (Member # 542) on :
Felix
You don't need to cover that much of the glass if you have a low pressure blaster....In fact I would reccomend it, all you nee to do is frost the glass....what about the vynull frosted look?
appliy it and hand cut the trim area.???
Posted by Felix Marcano (Member # 1833) on :
Thanks guys. Yes Kel, it is a giant shell. Beautiful place.
Posted by Felix Marcano (Member # 1833) on :
Mike, Vinyl was the very first idea, but the guy wants something permanent. I hear he has no problem paying for it, either.
Posted by Ricky Jackson (Member # 5082) on :
Felix, I would do that on the outside, not the inside. Not only would you not have to worry about getting the sand everywhere, it would look much better second surface from the inside. You can get sandblasting units that have a small enclosed space so you could possibly do it indoors but I don't think that would be an option. All said and done, it would look much better from the inside if it were blasted on the outside. I would probably use Hartco sandblast stencil, the thin stuff. You could probably charge about $10 sq.ft. for this job, plus materials and renting the pot and compressor. Do all the prep work first and blast when it's all done. You might want to consider doing it when there will be the fewest people around, maybe even at night. With the lights on inside that might be the easiest way to get the blast done nice and even (not that it will be difficult anyway). I'm guessing that the temps down there are like summer here in the south so you'll need an air supplied, air conditioned hood or you'll be hating life. Also, remember that sand is highly carcinogenic so wear a GOOD respirator, not the little 3M dust masks.
Posted by vance galliher (Member # 581) on :
Felix, for etch work I use clear shelving paper. 18" x 8 yds for about 6 bucks, adhesive not as agressive as vinyl...but agressive enough (vinyl is a pain to remove from glass)
Posted by William DeBekker (Member # 3848) on :
Chemical Paste/Acid Etch.. use normal Cheap vinyl for mask. Brush it on then wash it off/Neutralize with water. I would be nervous about sandblasting that inside and have you check to see if the glass is tempered. If its tempered you will have to be very very careful as you could easily have a window in a million pieces if you blasted to deep.
Its how we do tempered shower doors.
Posted by Glenn Taylor (Member # 162) on :
I am going to agree with William. My first thought was to wonder if the glass were tempered.
I would definitely go with the acid etch stuff if you can.
If you have to sandblast, just remember that it doesn't take much. I'd use a thin mask like Ricky recommended.
As for what to charge, I'd figure the cost of material and double it. Then on top of that, I'd guestimate how much time its going to take, multiply the time by your hourly rate and then add and additional 20% to help cover the incidentals that you just know will crop up.
Posted by Ricky Jackson (Member # 5082) on :
Just remember that acid etching with Armor Etch paste produces a "blotchy" effect on large surfaces. It's not noticed on smaller pieces but on large areas it can't be helped; it's an organic process.
Posted by Pete Payne (Member # 344) on :
personally, i would recommend a colured stripe,black, white maybe the railing colour, blasting won't be opaque enough when that close to the surface to hide the problem. I you do blast look into a vacuum recovery unit, they're slow as the blaster is a siphon unit, not pressure pot, but they have a vacuum nozel around the blast nozzle to pull the media back in. They cost about $600, but maybe you can find one to rent
Posted by Kelly Thorson (Member # 2958) on :
Felix, Make sure that your client is aware of the possiblility of glass breaking and willing to absolve you of liability. That's the rishk he is taking to get the look he wants. I think the blasting would be the nicest look, you may still see some of the shadowing of dark and light behind, but it will blur it enough that it won't jump out at you. If you can access some really large drop cloths and tape them to the window below where you are blasting, most of the sand should be easy to clean up. Just make sure you don't have creases that you can slip or trip or catch your ladder in.
Posted by Laura Butler (Member # 1830) on :
Makes sure he SIGNS a Release of Liability first, for glass breakage.
What kind of sand should he use? I would think that some silca would hang in the air...which you don't want to breathe.
Posted by James Coover (Member # 77) on :
You can use heavy cardboard (cut to fit) and secure with duct tape..be sure to double or triple up the duct tape closets to where your blasting...if you can't get duct tape to stick to stucco surface (if that's what it is) you could manually hold in place a cardboard or temperboard guide..much like a painter would do when spray painting. The cardboard could be recycled to the next window. Best etching results are achieved if you keep your tip moving and stay at a distance. I assume you know the proper grade of abrasive to use?? It is advisable to use an on off control at the sandblast tip. Be careful and good luck.
Posted by Dave Sherby (Member # 698) on :
Do not use silica sand. My supplier told me about a guy who thought it would be a great idea to sandblast the siding on his house. Afterward him and his family started getting sick. The health department condemned his house it was so full of free silica, and they even found high levels in his neighbors house.
Harbor Freight has a blasting unit on sale right now for $219. It has a nozzle inside a vacuum hose so you can blast indoors without making a mess. It sucks up the media as you blast so you can use aluminum oxide or silicon carbide (safe blasting media) and you recover the media and glass dust so you can use it over and over. I think you need to bring a compressor with you, but that's it.
We blast glass with Avery removable paint mask all the time. It holds up very well to the lower pressure used for glass blasting and will peel off the window much easier than other vinyl.
Posted by Felix Marcano (Member # 1833) on :
James, no. I don't know what grit!! What would you recommend?
Thanks Felix
Posted by Felix Marcano (Member # 1833) on :
Hey Sherby, I didn't find the pot you're talking about. Could you please email me the link? Thanks!
Posted by Dave Sherby (Member # 698) on :
I use 180 grit aluminum oxide for most of my work. Photo Brasive recommends 150 (coarsest), 180, 220, & 240. I like 180 because it cuts a little faster but still leaves a nice soft frost. For deep carving people use 150, but for tempered glass where you want just a light frost and very intricate designs 180 or 220 would be better.
This unit is a blaster and vacuum in one unit. I've read where you can go into restaurants and blast glass booth dividers, mirrors right on site. I've considered one for the shop because it would eliminate the need for a slide through cabinet.
Posted by Sam Staffan (Member # 4552) on :
quote:Originally posted by Dave Sherby: I've considered one for the shop because it would eliminate the need for a slide through cabinet.
Dave, I have a brand new one by Glastar. Next time you come through i can show it to you and work something out if interested.
Felix, same for you, I just did not know on shipping if that was something to consider getting it to you.
[ March 19, 2008, 11:56 AM: Message edited by: Sam Staffan ]
Posted by Felix Marcano (Member # 1833) on :
Sam, I gotta come up with something quick. I gotta start this job by Monday!
Thanks!
Posted by Denny Smith (Member # 6806) on :
We do a lot of jobs like this, but we have a self contained unit from Glastar http://www.glastar.com/catalog/sandblasting/OS-7.cfm We use low pressure, 180 aluminum oxide and with this particular unit, there is virtually no mess and no waste. If you're starting Monday, sounds like you already have the job - but did they agree without an estimate from you or are you just checking to see if you charged them enough? Looks to be a fairly simple job, will take a little time, but not difficult. You should do well - and with that view - I'd do it for a week away from Indiana Posted by Felix Marcano (Member # 1833) on :
Denny, if you would have responded earlier, I would have certainly taken you up on the offer... Always a pleasure to have letterheads here.
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