Backplate Polishing Advice

[Eric Sedletzky]

Don’t ever use a steel wire wheel on stainless that you plan to use in salt water. Use a stainless wire wheel. But I wouldn’t use either.
If you’re going to do this by hand use hand files. A small round chainsaw file works well for the ends of the slots to radius them, then use a small flat bastard file to round over the long parts of the slots and the perimeter. The bigger the flat file for the perimeter the better, so you might be buying several files but they’re cheap. Do yourself a favor and use a vice.
If you want to passivate the stainless after all your hard work you can buy some granulated citric acid used for canning and make a strong solution, then soak the plate in that and use a red scotch brite to clean off any staining. The citric acid will neutralize any ferrous metal residue and it won’t attack any of the other components/alloys of the stainless steel.

I know you want to do this on the cheap and all, but the most effective way to round over the outer edges of a plate is to use a 4-1/2” 80 grit flap disc grinder wheel on a small right angle grinder. It takes only a minutes.

 

[broncobowsher]

I know you want to do this on the cheap and all, but the most effective way to round over the outer edges of a plate is to use a 4-1/2” 80 grit flap disc grinder wheel on a small right angle grinder. It takes only a minutes.

80 grit is a bit course. I would be picking up one of my 240 grit flap disks. Slower, but smoother cut.

 

[Eric802]

Just use some files - flat bastard files for the straight edges and outside curves, round file for the inside curves. I spent about 20 minutes on my Hog SS backplate and it made a world of difference.

 

[Eric Sedletzky]

80 grit is a bit course. I would be picking up one of my 240 grit flap disks. Slower, but smoother cut.

No not really.
I do this all the time.
Anything less than 80 and you’re going to be spending a lot of time and creating a lot of heat.
240 may be good for polishing and getting deeper scratches out on a surface but for rounding over 80 works pretty good. After 80 I take a metal conditioning disc and go over it, the brown one. I also go over the slots with brown conditioning disc to smooth them out.
I have over 600 plates out there and not one complaint yet that the finish isn’t nice enough.

 

[NitroxSam]

When I did this:




I filed first with a med-fine set of files to take the big stuff off.
Then I went at it with progressively coarser [EDIT Doohhhh] higher/finer grades of this:

Abrasive Tape and Abrasive Cord

I also wire brushed it with a SS wire wheel.


One other tip: Be absolutely sure that files are completely clean of any other metal, wire-wheels are SS and have NEVER been used on anything but stainless, & virginity for any abrasive products and applicators. Otherwise you risk embedding contaminants into the SS plate which WILL corrode (rust). I have another plate which unfortunately suffered as a result of grabbing the wrong tool. (Sorry, Eric )

That's nice. What are the big triangular shaped cutouts on the bottom of the plate, near the lower harness slots for, to shave weight off the plate? How much does the plate weigh?

 

[-JD-]

The motivating factor for the machining was to turn it into a LW travel plate that would handle either single tank or Independent Doubles using only cambands (no adaptors).

The triangle cutouts allow the lower cambands to pass through (uppers pass around where the notch was made at the upper flare/main spine junction). They also allow an additional turn for the waist-belt anchoring. (I use individual webbing pieces in an H-harness so that I can move it between plates with all fixtures intact.)

 

[eelnoraa]

No not really.
I do this all the time.
Anything less than 80 and you’re going to be spending a lot of time and creating a lot of heat.
240 may be good for polishing and getting deeper scratches out on a surface but for rounding over 80 works pretty good. After 80 I take a metal conditioning disc and go over it, the brown one. I also go over the slots with brown conditioning disc to smooth them out.
I have over 600 plates out there and not one complaint yet that the finish isn’t nice enough.

damnnn, I have been using 400 for polishing metal. I will try 240 next time. Need to learn from the best. You plate is definitely the best finished the plate I have seen.

 

[Eric Sedletzky]

damnnn, I have been using 400 for polishing metal. I will try 240 next time. Need to learn from the best. You plate is definitely the best finished the plate I have seen.

Well hold on, I was talking about rounding over edges not actually polishing the face.
If you want to polish the face here’s how I do it.
After all grinding, hammering, etc. is done, I take 220 on a direct drive 3” hook & loop pad and go over it. Then it gets 400, then it get 800, then it gets 1200, then I go to polish with one of these airway wheels (on edge not flat) on a large buffer with black emory

Then it gets the same wheel with green rouge, then blue coloring rouge.
Basically it’s all the same stuff a polisher would use on big rig wheels etc. except I use all the stainless stuff.
Then you got a mirror.
And no stainless is not soft, it’s a bitch to polish.
Aluminum polishes like butter compared.