HomeSmith What if? : Spot rebluing

[Shotguncoach]

I've been wondering for a while what would happen if I tried only rebluing part of a gun and not the whole thing. We're all familiar with using cold blue for touchups.....can slow rust bluing be used the same way? My theory is that it depends. A big scratch right in the middle of an otherwise pristine sideplate probably won't work, but a distinct area that is somewhat separated from the rest of the gun might be possible. Let's find out.

Our test sample for today's adventure is a Model 15-3:





From those two pictures you may be saying "But that's a nice looking gun Coach, why are you messing with it?"

I got this one cheap because it's an overseas re-import and because of this:



...and this:



...and this:



I'm not sure if it's holster wear, storage wear, or from shooting wearing chain mail gloves, but the top strap and the area immediately below it are rather nasty. I'm only into this gun for a couple of hundred bucks, so it's a perfect candidate. If things don't go well I'll just dip the whole thing and reblue it all.

Step 1 was to move all the insides to the outside and give it a good scrubbing. The sideplate has some stories to tell about how the insides are working, but we'll get back to that later.



A piece of 240 grit sandpaper was used to finish removing the old blue from the top strap so that we could see what we had to work with.......and there they were: rust pits. Sandpaper wasn't going to be enough for those, so a #2 file was chalked up and we went to work.



Of course there were pits on the top too. Having them only on the flat part would have been waaay to easy.



Always work on the round part first, then do the flats. That way your last step restores the edge line instead of taking it away....



When the pits were gone and the edges edged again, some 240 sandpaper was used to clean up the file marks. The sides of the frame were sanded front to back, while the top strap was sanded top to bottom using only downward strokes to simulate the pattern that would be obtained from briefly touching the top strap to a belt sander. The downward strokes wrapped around the curve and got progressively lighter until it was only the weight of the sanding block providing pressure.



Then the entire process was repeated on the other side. This picture caused me to go back and do more work because I hadn't noticed the row of small scratches near the sight channel until I saw it on my phone.



I chose not to do any sanding on the sideplate. If things don't work out I can always go back and do that, but this is an opportunity to demonstrate what would happen if the scratches were reblued without any other prep.




After attaching some zip ties to the frame and sideplate, both pieces were degreased with spray brake cleaner and it was rubber glove time.

The sideplate received one swipe of a pad barely wet with 25% rusting solution and was immediately wiped dry with a clean pad. The idea is to very slowly add color only to the scratches without disrupting the other finish.

The frame received one swipe on every area that was in the white using 100% rusting solution. These areas are bare metal and need a better "base" for the rust blue to build on.

Both pieces are currently hanging in the bathroom for their first 2 hour rust. After a nap, we'll boil them, card them, and do a quick inspection to see if we're headed in the right direction.

 

[2152hq]

If doing touch-up bluing to areas, using Scotchbrite to polish out the scratches in the existing bluing works well.
If you have to use grit paper first, then use scotchbrite to blend the polished area into the original polish.
Use dry or with a little oil or even water, it will make a difference in the luster you get. Even using worn pads works well to get different looks to the polish.

Blending the new rust blue into whatever sort of bluing exists on the surfaces around it can be tricky. The existing blue may not want to accept the bluing soln well.
Even with careful cleaning, it will not 'wet' the surface and you get patches of soln and then patches of rust on the old blue instead of a nice even layer.

To bypass that, use the scotchbrite once again in it's finest grit/cut and very softly polish the existing bluing. No matter how beautiful it looks,,you have to cut the surface of it to allow the bluing soln to get a an even hold and rust evenly.

I find doing a non-directional very soft polish does a nice job of it. It breaks the surface but does not go thru the blueing at all.
That's all you want it to do.

When you do your rust bluing, cover the entire surfaces with soln,,not just the repaired area. Otherwise you will build a color difference line where you try and blue the repair but not the otherwise untouched orig blue.

It'll take a few cycles but they will all catch up with each other.


You can use that same technique to fix up an in progress bluing job where a blemish or discoloration area pops up while in the process.
Instead of stopping, stripping all the bluing, re-polishing and starting the bluing all over again..

Use the scotchbrite to scrubb that discolored, damaged, don't look right area down till the damage is gone.
You may go right thru the bluing you have done so far, and right to bare steel. But don't be concerned with that.
Blend the polished area out as above to surrounding the new rust blue. But you do not have to polish all over the new rust blue as above.

Now go back and continue with rust bluing.
Cover the repaired area AND the entire rest of the part with a coat of soln. Let rust.

Keep doing this complete coverage cycles as the repaired area catches back up in color with the rest of the part.
It won't take all that long,,maybe 2 to 3 cycles before the damaged area that was scrubbed back down to bare steel is completely gone and the color matches again.
I still apply a couple extra cycles to build color after it matches.

Keep the rusting light and you can keep a lot of the luster of high polishes.
It doesn't take a lot of viewable rust on the surface to produce a coating of color when boiled. Almost none actually. You can feel it more with your finger tips when lightly gliding over the surface than anything else. If you can,,then it's time to boil.

 

[Shotguncoach]

Thank you Sir....I always appreciate your advice. I'll give both pieces a scrub with some scotchbrite after the next boil and before the next rust.

Here are the pieces as they came out of the first boil:








And after the first carding:

 

[Shotguncoach]

After the 2nd cycle with the 25% solution:



After the 2nd cycle with 100% solution:





Both pieces were scuffed very lightly with a white scotchbrite pad before the 3rd cycle began. The sideplate is coming along nicely with the 25% solution that is wiped off immediately after application. Yes, I do throw away the patch that is used to wipe off the part....I don't want that laying around to contaminate something else.

The frame may appear to be lagging behind but I've found that with some guns this process is somewhat of a "gradually, then suddenly" kind of thing.

The 3rd rusting is in progress, with the sideplate using the 25% solution again and the frame using 50% this time.

 

[Shotguncoach]

We’re up to cycle #5 right now. The sideplate scratches are still visible under the blue when the light is at the right angle, which was expected. I didn’t try to remove them - I wanted to see if I could color them in. That seems to be working so far.



The frame is coloring up nicely as well…



We’ll check back in on Saturday after a few more cycles and see how it turns out.

 

[Shotguncoach]

So how did our experiment turn out? So so.

The area of the sideplate that had the big scratches came out ok. The scratches still show in the right light but the are much better. That part worked better than I expected.



The top strap also worked well. The matte finish actually looks good on the top.



Where it did NOT work was the area of the side of the frame just above the sideplate and the flat above the cylinder window. I think that stopping at 240 grit was a mistake.



So what did we learn? 2152hq’s advice about using scotchbrite and putting the solution on the entire piece worked well on the sideplate. The scratches did not fill in, but they did take the color and are much less noticeable. Sanding the top strap with 240 grit from top to bottom also worked well.

The next time I have the bluing stuff set up, I’ll re-sand the areas on the sides that ended up with the dull finish and take them to 1000 grit and then try again.

Not a 100% success, but I learned a new trick (thanks again to 2152hq) and also learned something NOT to do….both are important.