TIPS for Blasting Signs WITHOUT Owning Blast Equipment...
First try Monument Companies...
Likely the first thing you will hear is "NO...We don't want to contaminate our blasting booth"...
Sandblasting wood creates fine wood dust that makes abrasive reclaiming (more than one use) Quite a Problem.
The wood particles left in the abrasive mix will add a substantial "dust cloud" to the 2nd use blast and greatly reduce visibility and cutting power, along with compounding moisture problems.
BUT...Most monument companies have smaller portable units for on-site blasting, cleaning existing monuments, etc.
Many will do this for you outside their blasting booth, if their location permits. Many will already have experience with blasting wood signs and will do this for you at an hourly rate.
Most monument companies use fine grit abrasive. Although I prefer Medium grit abrasive for redwood and painted or rusty steel, fine grit can actually help to bring out the grain with western red cedar. Fine grit is a must for blasting HDU.
Medium grit gives more speed time wise, but requires larger equipment....
For those first wanting to try it, go FIRST and WATCH someone else do it...Look at all the equipment, the abrasives, and especially the protective gear.
Another option to look for will be painting/sandblast contractors with portable set ups. Another option will be steel fabricators and those specializing in equipment restoration.
An important Issue here and in discussion to follow...Is definitely your LOCATION.
In more crowded commercial locations and those near residential areas, there are likely codes to prevent this activity on your site. All this must be researched beforehand, PLUS all the safety aspect research.
The NEXT OPTION for those that want to try it themselves is RENTING the Blasting Equipment...If your location permits.
Having done your homework and researched ALL safety aspects, you will also know what to ask for with Renting personal protection Gear, that is Sandblast Hood and approved respirators...One will likely need to buy the approved respirator, so research on that is imperative.
Most rental companies will have several choices for portable compressor units, likely starting about 100 CFM to 185 CFM and larger. (CFM=cubic feet per minute air supply)
These will supply a Continuous air flow (CFM) at 75 PSI to 110 PSI of constant air pressure.
(PSI=pounds per square inch air pressure)
Most heavy duty sand pots require this constant air pressure to do a good job...
Output air pressure from the sand pot is also maintained by the size of the orifice hole in the ceramic nozzle on the end of the blast hose...
Sandblast Pots need to be Rated and Matched to the size of compressor output. Heavy duty sandpots will range from 100 lb. To 300 lb. and larger. Most are sized from .5 cubic foot, 1 cu.ft., 3, 4, 5 cu.ft., etc. This is the amount of abrasive they will hold.
This size factor determines how often you will have to stop blasting and refill the sandpot.
The air supply hose and abrasive output hose are sized (inner dimension wise) to the air supply and the abrasive grit size.
The ceramic blast nozzle on the end of the output hose is sized according to abrasive grit and air supply.
Higher CFM and PSI translates to the time it will take to complete the blast job, directly related to the force of abrasive output from the sandpot.
I must say for those just starting out, it's best to try a 100 lb. sandpot because of weight and ease of setup.....300 lb. sandpots are quite heavy and bulky, and require larger and more cumbersome hoses.
Set up of the equipment usually takes me about an hour by myself...I usually want to have other things to sandblast, such as several signs or other steel equipment or steel parts, when I do the blasting...
I will also recommend this, for those renting equipment, to get your money's worth out of rental costs...You will see an example of this in the following photos...
The next step will show the blasting process...
I have finished the blast on this sign, taken some photos, just need to type some explainations....
To be continued...
JimmyG's Signs & hieroglyphics
Register, Georgia . . . . . . . . . . . . . local colour FINE SIGNS since 1980
slightly out of register......a drop shade away from statesboro blues...
a tad bit offbeat and indeed a fine tone of local colour....
designs, graphics, blasted redwood, hand-lettered painted signs, illuminations, metalworks, and other artful deeds that get installed into reality or maybe carved in stone.....
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