Aluminum texturing options (was hammered finsh thread)

Big wire wheel in 'artistic' hands?

I've seen textures like that applied to glass. Sorta. So sandblasting might be worth a shot. Probably expensive since making the pattern might take a lot of artistic touch on the part of the operator (depending on what kind of random resists they can do).

Or still in the hammered vein, maybe a shot blast wheel would do it. Basically steel shot thrown into a centrifical blower, hurls it at the work (usually scale and sand stuck to an iron casting, so you might want to call a local foundry and see if the foreman is interested in helping out), leaving small dents. May or may not have the problem of warpage.

Tim

Wheelabrator. Most of the shot and abrasive is small, but you might get lucky. Call up Wheelabrator or your local foundry. These machines truly come in all sizes.

This is not an easy thing to do. The aluminum is soft enough it will warp, and it is tough, but not impossible to get it back flat again. Big rolls- you will need 4' wide rolls, that will roll 1/8", and run it back and forth a bunch of times, and as long as you havent overdone it, and created some bowls, that will take it back pretty flat. My advice, though, is not to try to texture aluminum sheet yourself. Consider a few other directions-

1- buy pre textured sheet. The big dogs in this field is Rigidized, in Buffalo New York- they make pretextured sheet in a wide range of patterns, in a variety of metals. Their main thing is stainless, which is better than aluminum for this anyway- it takes a texture better, its harder so it will wear better, its thinner, lighter, tougher, and resists oxidisation better too. Aluminum will oxidise, and get white junk on it, unless you clear coat. The stainless will just sit there. However, if you insist, I am pretty sure Rigidized will roll aluminum for you. you must texture aluminum, the way it is done is with textured rolls- 4' wide, probably a minimum of 4" in diameter, with the texture ground or pounded into it. Then the aluminum is fed thru, powered, of course, minimum of maybe 3hp to do this. 1 shot, the whole piece is textured. This is how rigidized does it. I realize, this is not cheap or easy- but what you wanna do isnt common, and there is a reason for it. 3-Other metals are gonna hand texture a whole lot better than aluminum. I have been texturing a lot of stainless lately- I use needle scalers, with a variety of modified needle shapes, and air chisels with modified tips. Stainless is hard enough it doesnt wanna bowl near as much. Of course, we still have to run it back and forth thru the rolls a few times, flipping it, to get it flat again. But I have been having good success with 1/8" 304 sheet this way. 4- I am not sure how your etching is gonna work- thats something I dont know much about. But I have also done texturing of surfaces like this with sandblasting- you can get this cool adhesive backed rubber sheet, in rolls. You cut out your pattern with an exacto knife, and peel off the negative parts, then blast. Works pretty well, with the time spent blasting controlling the depth of the texture. You could buy the rubber yourself, then pay someone who is setup to blast. The rubber stuff can be gotten at big signmaking supply companies- they use it to make sandblasted wood and stone signs. TP has it too.

Never tried this but .. How about a big pavement roller? Lay the sheet on exposed aggregate concrete or gravel and drive over it with that big steel roller. Seems like it should stay flat or at least you could flip it over and flaten it?

Folks keep recommending this method, but forgetting the top platen. You cannot just hard-roll the sheet onto a pebbled surface, and expect to get deep, well-defined textures.

Instead, place the sheet on the aforementioned aggregate slab (or make your own with clean aggs on a clean, flat slab), then cover it with a single layer of the same sized aggs. Then roll. The top and bottom aggs will "nestle" within each other's gaps, yielding a heavy pattern.

You'll still have to do some flattening afterwards. But with both negative and positive platens, you'll get deep embossing, and little "dishing".

LLoyd

Ben- I tried to email you directly, but CMU says that is not a valid email address.

I have used a lot of rigidized over the years- both on architectural applications like yours, and on sculptures. There is a lot of rigidized stainless in my camshaft benches at the Great Mall stop of the San Jose rapid transit-

16 ga stainless is used for the 4 foot diameter ends on the benches- something like a dozen sheets of the stuff. lot of the stainless has been hand textured on my fence for the Del Mar station on the Pasadena Gold line of the MTA. was mostly done with needle scalers and air chisels, but some of it was done hot, in a power hammer.

Clients always want it now, and for nothing, and when you are starting out, unfortunately, you have to take some of those jobs. But extreme metal manipulation takes experience, time, machinery, and money. You cant do everything with hand tools by yourself. Interesting that the big dog architects and the rich clients are always the ones who want the most, but arent always willing to pay for it. Who else is gonna do it? There are only a few fabricators I know of who do this kind of work right, and they charge really big bucks- people like Metalmorphosis in LA, or Fabrication Specialties in Seattle. If either of them was quoting your job, you can bet it would be hundreds of bucks a square foot. And their solutions might include things like casting the sheet in a foundry. Rolling big sheets flat again is always iffy- I have done a lot of jobs where we cut a lot of detail out with plasma cutters, which puts internal stresses and bends in the sheets- sometimes it can be rolled out, sometimes not. Back and forth, with a slight curve, seems to work the best. Breaking the piece into smaller sections, with the break lines as part of the design, would help a lot, as those big sheets are just a bear to work with.

Good Luck

ries

Ben- I tried to email you directly, but CMU says that is not a valid email address.

I have used a lot of rigidized over the years- both on architectural applications like yours, and on sculptures. There is a lot of rigidized stainless in my camshaft benches at the Great Mall stop of the San Jose rapid transit-

16 ga stainless is used for the 4 foot diameter ends on the benches- something like a dozen sheets of the stuff. lot of the stainless has been hand textured on my fence for the Del Mar station on the Pasadena Gold line of the MTA. was mostly done with needle scalers and air chisels, but some of it was done hot, in a power hammer.

Clients always want it now, and for nothing, and when you are starting out, unfortunately, you have to take some of those jobs. But extreme metal manipulation takes experience, time, machinery, and money. You cant do everything with hand tools by yourself. Interesting that the big dog architects and the rich clients are always the ones who want the most, but arent always willing to pay for it. Who else is gonna do it? There are only a few fabricators I know of who do this kind of work right, and they charge really big bucks- people like Metalmorphosis in LA, or Fabrication Specialties in Seattle. If either of them was quoting your job, you can bet it would be hundreds of bucks a square foot. And their solutions might include things like casting the sheet in a foundry. Rolling big sheets flat again is always iffy- I have done a lot of jobs where we cut a lot of detail out with plasma cutters, which puts internal stresses and bends in the sheets- sometimes it can be rolled out, sometimes not. Back and forth, with a slight curve, seems to work the best. Breaking the piece into smaller sections, with the break lines as part of the design, would help a lot, as those big sheets are just a bear to work with.

Good Luck

ries