FAQ

Big Blue Saw began offering finishing options in 2009 to help parts look great and fit in assemblies. Finishing is most critical when the parts are highly visible or are handled by an end user, rather than deep inside an assembly. Parts fresh off the waterjet often have a burr on the bottom face, marks from handling, frosting near the cut line from overspray, and vestigial tabs from being held in place during cutting, among other issues. Applying a finishing process to parts post-cutting will help you get parts that need minimal cleanup before installation. Now, with our expanded list of finishes, Big Blue Saw offers more options for your finished parts.

 

Raw Finish (No processing)

Copper Raw Resized 
Raw Copper

304 StainlessSteel Raw Resized 
Raw 304 Stainless

 Aluminum Raw Resized
Raw Aluminum
 Brass Raw Resized
Raw Brass
 Raw Carbon Steel Resized
Raw Cold Finished Carbon Steel

This process is the most common option for parts that will not be seen or handled, or if you will be applying your own finish once you receive the parts from Big Blue Saw. There will be some overspray from the waterjet near the cut line, especially at pierce points and on the bottom face. There may be minor marks from handling on the top and bottom faces and from exposure to water. Some metals also have mill marks from the manufacturer. Most of the mill lacquer printing can be removed with solvents or fine steel wool.

On smaller parts where one or both dimensions are less than 4 inches, we have to tab the part to the sheet during cutting to keep them from ending up at the bottom of the waterjet tank. In these instances we allow the techs to decide to pop them off the sheets or ship you the sheet with the parts still attached. This allows us to ship orders faster as well as keeping very delicate parts separated and contained during shipping. If you know that you want your parts to absolutely ship separated from the sheet with the tabs ground down, you will want to select one of the finishing options below or "Remove Tabs" and not raw parts when ordering.

 

GlassBlast Finish

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GlassBlast Finish removes burrs and surface imperfections while providing a very fine grain finish across the entire part. We apply this finish by blasting the parts with a high pressure stream of tiny glass beads. This option is an especially good match for waterjet cutting, as the surface resembles the cut edge produced by the garnet from the waterjet, meaning that the finish on the faces and cut edge matches closely. GlassBlast finish is a great option if you plan to paint your parts post cutting as the even "tooth" of the surface really allows paint the nooks and crannies it needs to get a good hold of the surface. It is also a great option when you are looking for a matte finish.

To apply the GlassBlast Finish, the parts must fit in our blast cabinet. This means that parts must be less than 24 inches in both height and width. We also cannot apply GlassBlast to parts less than 1 square inch, as parts this small are hard to hold and apply the finish evenly. Parts given GlassBlast will always be removed from their source sheet and have their tabs ground off (see Remove Tabs) in order to make the edges as clean as possible.

Copper GlassBlast Resized
Copper with GlassBlast 
 304StainlessSteel GlassBlast Resized
304 Stainless Steel with GlassBlast
 Aluminum GlassBlast Resized
Aluminum with GlassBlast
 260Brass GlassBlast Resized
Brass with GlassBlast
CarbonSteel GlassBlast Resized
 Low Carbon Cold Finished Steel with GlassBlast

PadPrep Finish

hand sander2resized1

Similar to our older “Basic Finish”, these parts are finished on both the top and bottom faces with a powered non-woven abrasive pad in a random orbital pattern. Many of our signage clients use this finish for signs as the allover brushed finish looks good in a wide variety of locations, and the texture left behind by the abrasive pad also provides a good "tooth" for paint to hold on to. All light surface scratches and mill marks are removed. Burrs are eliminated as well. This finish can be done on parts that are 6 to 8 inches or larger. Got a smaller part you would like an allover brushed pattern on? See our tumbling option below.

With PadPrep, we also remove parts from the source sheet and grind flush any vestigial tabs to prevent them from snagging (see Remove Tabs).

copper pad prep resized
 Copper with PadPrep
304ss pad prep resized
 304 Stainless Steel with PadPrep
pad prep Aluminum resized 
 Aluminum with PadPrep
 Brass pad prep resized
Brass with PadPrep
carbon steel pad prep resized
  Low Carbon Cold Finished Steel with PadPrep

 

SlickStripe Finish

belt sanderresized3

With the SlickStripe Finish, both sides of the part are finished with a non-woven abrasive on a belt sander, giving a brushed finish with parallel lines. While parts with this finish look great on your wall and would make most clients satisfied, this is not a perfectly even #4 standard finish, as it is applied by hand. Due to the limitations of our machinery, parts given this finish must be less than 6 inches in either height or width. If you have a specific preference for the direction of your brushed lines, please contact our customer advocates to set up a special order that calls out belt direction.  

 Copper SlickStripe resized
Copper with SlickStripe
 304StainlessSteel SlickStripe resized
304 Stainless Steel with SlickStripe
Aluminum SlickStripe resized 
Aluminum with SlickStripe
 260Brass SlickStripe resized
Brass with SlickStripe
carbon steel SlickStripe resized
Low Carbon Cold Finished Steel with SlickStripe

 

TumbleClean Finish

tumbler1resized3

TumbleClean Finish is an inexpensive way to remove burrs, reduce surface marks, and produce an even texture on smaller parts. We place parts for TumbleClean in a vibratory tumbler with ceramic tumbling media. This combination of movement, water, and media puts a smooth and even surface all over the surfaces of the part. This is great if you are looking to prep small jewelry parts or electrical connectors before further polishing or soldering. It is also a great way to process a lot of small parts for production work.

Parts which have TumbleClean applied must be smaller than 4 inches in both height and width. Also, the stock material must be strong enough to handle the tumbling process, so stainless steel parts must be 0.03 inches thick or thicker. Aluminum and other non-ferrous metals must be thicker than 0.045 inches. With TumbleClean Finish, our techs will also remove any tabs by grinding so that they do not appear on the finished part.

Copper TumbleClean Resized
 Copper with TumbleClean
304StainlessSteel TumbleClean Resized
 304 Stainless Steel with TumbleClean
Aluminum TumbleClean Resized
 Aluminum with TumbleClean
 260Brass TumbleClean Resized
Brass with TumbleClean

 

Remove Tabs

Waterjet cut parts are often tabbed to the source sheet when cut. This prevents them from falling into the waterjet tank or tipping up and getting damaged during cutting. With Remove Tabs, our techs will break the tabs to remove the parts from the source sheet, and then grind any leftover tab material to be flush with the part. Remove Tabs is available as an option on pieces where both dimensions, height and width, are less than 4 inches. Parts larger than this will automatically have this process applied.

Without this service, Big Blue Saw techs have the option to leave the parts tabbed to the source sheet and ship the entire sheet to you, or remove the parts from the sheet but leave the vestigial tab. 

GlassBlast, PadPrep, SlickStripe, and TumbleClean Finishes automatically include Remove Tabs. You don't have to select this service if you are purchasing one of those finishes.

 

Metal Reactivity

One aspect of metal finishing you should also be aware of is how reactive the materials you are ordering are and how mill materials are shipped. We make every attempt to keep our stock materials clean, dry, and minimize scratching when handling, however, the sheets we order from our suppliers do not have pristine surfaces. Waterjet cutting also uses abrasive materials and a cutting method that is not conducive to pristine mirror polished sheets or sheets

with coatings. Most suppliers process mill sheets with a thin layer of oil on the sheet to minimize oxidization. That coating is removed when we apply these finishes so highly reactive materials like copper, brass, and carbon steels will quickly start to display tarnish after processing. While not as difficult to remove as tarnish, the stainless steel parts will show fingerprints from handling as well. 

Most non-abrasive jewelry cleaners will remove the tarnish on copper and brass materials, while many of our techs use denatured alcohol or other solvents to bust fingerprints off of stainless steels. Very stubborn oxidization on parts can usually be scrubbed off parts using polishing cloths or 000 steel or bronze wool. Just be sure to work in the direction of the finish applied. A dab of clear microcrystalline wax like Renissance brand microcrystalline wax worked into the surface of your part can keep it resistant to oxidization. Some metalworkers also suggest clear polyurethane and paste waxes as options for keeping oxidization away. 

We make every attempt to wash and dry parts quickly so that they don't turn during shipping. That said, our shop is in Georgia, which is very humid. If you would like our techs to apply a moisture repelling oil to your parts, contact our customer advocates to setup a special order with that service.