The Letterville BullBoard: Sandblasting HDU/Signfoam

This is topic Sandblasting HDU/Signfoam in forum Old Archives at The Letterville BullBoard.

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Posted by Rick Collins (Member # 2002) on :

I've been sandblasting redwood signs since 1978 & have always rented a trailer mount compressor (125-185 cfm @100 p.s.i.) & pressure pot. For the past year I have started using "Signfoam" mainly because of the decreasing availability of redwood. I talked with the folks at "signfoam and they are telling me that a 5 HP compressor, 80 gal. tank,80 p.s.i.,1/8" tip nozzle & aluminum oxide is sufficient for sandblasting "Signfoam". Before I buy a set-up as this I need some feedback from any pro's currently sandblasting HDU with a similar set-up, such as scfm, pressure, compressor HP, tank size, pot size, medium/alum. oxide and grit and finally approx. time to sandblast a 4'x8' sign. Lot of questions I know, but it's easier to ask the question than to pay for set-up I can't use efficiently.
Thanks in advance!
Rick

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Rick

Posted by Jack Davis (Member # 1408) on :

http://www.imagemakerart.com/photos/sample1.jpg
This is about a minutes blasting with a unit like you speak of with a siphon pot. I will get a pressure pot next time. I'm sure it will cut my time in half. My guess is that to do about 4 square feet of reasonable depth on a sign with average artwork would take 15 to 20 minutes. The piece shown here is a sample of texturing and is about the size of your hand. This size unit would even touch redwood, but is good for average glass frosting.... Bronzeo

The photo is getting kicked out for some reason, so just click the link; it works.

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Jack Davis
1410 Main St
Joplin, MO 64801

[This message has been edited by bronzeo (edited February 27, 2001).]

Posted by Henry Barker (Member # 174) on :

Hi Rick,

Welcome here, I sent you a mail last night..hope you got it OK...I found a link here which might help you
http://www.letterhead.com/ubb/Forum1/HTML/004643.html

Hope this link works

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Henry Barker #1924
akaKaftan
SignCraft AB
Stockholm, Sweden.
A little bit of England in a corner of Stockholm
www.signcraft.se
info@signcraft.se

Posted by Dave Sherby (Member # 698) on :

Rick, I can't speak from experience with the set up you are thinking about, but just in case you don't get any other responses, I can shed a little light on your querry from blasting both redwood and HDU.

The guys that make the GrainFraim use that exact setup. I know they blast ALOT of signs. They have given me alot of information and have never steered me wrong. Everything they have told me is right on.

They said the key to using a compressor as small as 5 hp is the 80 gallon tank which gives you enough reserve air for this setup to work.

I am currently using a 100cfm compressor with a 1/4 inch tip. I am blasting outdoors with silica sand (until my indoor booth is finished. Then I'm switching to aluminum oxide) I find that blasting HDU takes less than half the time (if that) as blasting redwood. I blast redwood at 90 psi and foam at 65 psi. I just noticed that Precision Board recommends even less pressure, around 50 psi.

Since my set up blasts HDU at half the time as redwood at less pressure, I would think a 1/8 inch tip would blast at least at similar time on foam as a big rig on redwood. Also I've been told that aluminum oxide cuts much faster than sand. Of course the key to using aluminum oxide is to use it over and over, foam dust and all. Most shops replace their Al Oxide about once a year which makes it cheaper than sand in the long run. You can only blast foam with it though. When I do an occasional redwood piece, it will be with sand outside, keeping the indoor blasting on HDU only with aluminum oxide.

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Dave Sherby
"Sandman"
SherWood Sign & Graphic Design
Crystal Falls, MI 49920
906-875-6201
ICQ: 21604027
sherwood@up.net

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