Sanding 304 Stainless

[erikmannie]

On all sanding grits finer than 50 grit, I work on only one side until it is done.

Previously, I had a production line set up, but one can easily lose track of what grit has been completed on each side with a production line.

 

[erikmannie]

I see that I am paying about 36 cents for each 5” sanding disc (for use on the 2.9A orbital sander).

My brother was surprised how much we were spending on abrasives, so I only have 3 sanding discs in each grit for each side. By the way, one side is 5’ long X 1-1/2” wide.

I will probably be earning about $15 an hour for my sanding labor. I am happy to do it for the love of the game & an opportunity to produce quality work. For his part, my brother is getting a screaming deal.

My $40, 4-1/2” angle grinder died yesterday while removing that “moonscape”. I believe that I got my money’s worth out of it in 2-3 years.

 

[erikmannie]

Here is my setup today. I am waiting on 2 separate orders of sandpaper, so all I can do today is take everything down to 120 grit.

I’m also doing the edges (i.e. the .125” wide side).

I put some 1“ x 1“ square aluminum stock under it to protect it.

The Sharpie is very important to mark what I have done so I don’t get lost.

 

[erikmannie]

All of the remaining sandpaper has come in. This project is going to be done in 4 days, at which point it goes to the paint guy for clearcoat.

One of the useful things that I learned from this project is that cold rolled stainless has a nice surface finish, but hot rolled stainless does not. In fact, the surface finish of the hot rolled stainless that I bought for this project was very poor. What is more, I believe that you can only purchase .125” angle stainless in hot rolled.

Never again would I flap disc + sand this much hot rolled stainless myself. Rather, I would take it to a metal finisher/grainer even though this means driving a long distance to the professional, waiting for who knows how long, & then paying their bill. I hope I never find out how much a metal finisher would charge to do this, but I’ll bet that it would be over $1,000 for 8 quantity 5’ lengths of 1-1/2” SS angle.

My customer paid $900 in sanding labor + over $400 in 40 (32?) grit (blue) poly-strip discs, 180 grit flap discs, 50-120 grit sanding belts, & 40 to 320 grit 5” sanding discs.

It is going to turn out *really nice*, but who wants to spend at least 60 hours using a flap disc, belt sander & orbital sander on angle stainless? I would rather spend my time on a machine tool or welder.

 

[erikmannie]

One huge mistake that I hope I never make again is advancing to an 80 grit sanding belt before it has been made perfectly flat with the 50 grit sanding belt. You can get it done with the 80 grit sanding belt, but it uses a lot of belts & is a waste of time.

This is so important that I will probably go over it with another 50 grit sanding belt even after it appears to me to be flat.

 

[erikmannie]

These arrived tonight. I guess that I will be using all this (and more not shown!) within the next 72 hours because I told my brother that this project will be done in 3 days.

250 sanding discs for an orbital sander:

 

[erikmannie]

I finally graduated from the belt sander. That took such a long time! Everything is 100% flat & has seen one 120 grit sanding disc. I also did all of the (5’ long X .125” wide) edges down to 120 grit.

Now I only have the 3.0 Amp random orbit sander and 296 sanding discs. Here is today’s setup:

 

[erikmannie]

So I have finally finished one side. This is sanded to 320 grit, & is hopefully good enough. It is getting a professional clearcoat.

I am actually not happy with it because there are scratches left behind from coarser grits. The customer specification for surface finish is that “it looks good from 6’ away”.

I wear 2.25X glasses while I work, so it is magnified for me.

 

[Firstram]

UsIng a block of wood and red scotchbrite, wet sand in the long direction. Compare that to what you have now, you might be happy with the finish. Have you considered skipping the clear coat and just passivating the stainless? That will keep the rust at bay.

 

[erikmannie]

My brother definitely wants the clear coat. *The surface finish that I am going to post below will have to be good enough* because I need to move on to other projects. I only made about $10-$15 an hour for my sanding work, & such work is not my favorite. If I were to do this again, I would absolutely send it off to a professional metal finisher.

One of the sides seen below does not matter because it goes up against a 4” X 4”.











This piece looks really nice in person. The pictures posted above are zoomed & (insert other desperate excuses here).