Restoration of a Bead Blast part to Natural Finish

[Tom R.]

I've gone through the archives searching "finishes" for natural metal items and curious if anyone has a "technique" for removing the "bead blast" look on an item prior to use of a rust preventative such as WD40 or PreLube 6?

For example, you've bead blasted a strut but wish to restore the natural metal look prior to application of WD40. What works? Sand? Wire Brush? Polish? Other?

[Harmon C.]

Re: Restoration of a Bead Blast part to Natural Finish

If they need bushings the complete strut rod in reprduction is very close to an original but lately some have had problems with the bushings. If you blast them use the lowest pressure and black magic. Glass beads make a smooth finish for painting but not for this part. Rubbing black and gray paint on them an wiping most off will look the best but expect some deduction on this part.

[Dick W.]

Re: Restoration of a Bead Blast part to Natural Finish

Gun blueing. Use the cold blueing varity. Gives the heat treated look

[Tom R.]

Re: Restoration of a Bead Blast part to Natural Finish

Gun blueing. Use the cold blueing varity. Gives the heat treated look

Interesting...cold bluing. I suppose if you applied with steel woole, it would blue while also flattening the matte finish from the bead blast.

[Chuck S.]

Re: Restoration of a Bead Blast part to Natural Finish

...I suppose if you applied with steel woole, it would blue while also flattening the matte finish from the bead blast.

I'm not sure any surface finish will make a bead blasted part look smooth again except a nice thick coat of paint. Sorry, Dickie, I disagree on gun blueing; if it will not cover the machining marks on a receiver, then it won't conceal bead-blasted texture either.

The matte finish of bead blasting is actually NOT smooth as posted: "Smooth" is relative. Bead blasted surfaces are near-microscopically textured, and therefore bead blasting is an excellent prep for PAINT. To wit...bead blasting any "smooth" parts that are unpainted, or natural, is going to create additonal problems for you.

Burnishing with steel wool WILL remove the matte appearance and shine the part back toward natural...the longer you burnish, the "shinier" the part. I'm not sure HOW burnishing with steel wool does this; maybe by smoothing the "bumps and dips" to remove the texture; or maybe by shining up the "dips" and leaving the texture invisible. Probably the former is correct.

A strut rod would seem to be a poor example for returning to a smooth shiny surface...the early ones I know about were forged, and therefore inherently rough. I don't know about the later ones; maybe they were fabricated from cold rolled rod and tubing..

The toughest parts to return to "as-manufactured" appearance following bead blasting are stamped sheet metal items like headlight actuators or relay covers. Burnishing with steel wool will bring stamped parts back to acceptable, but they are not as original.

You can not plate on top of the bead blast texture and get an original finish...if you do, your plated part will have a dull matte appearance because plating is not thick enough to fill the texture. The best cleaning method for smooth stamped steel metal parts is judicious use of muriatic acid...it will leave the surface smooth as original, but clean.

This is what I've learned from the University of Hard Knocks.

[Tom R.]

Re: Restoration of a Bead Blast part to Natural Finish

Burnishing with steel wool WILL remove the matte appearance and shine the part back toward natural...the longer you burnish, the "shinier" the part. I'm not sure HOW burnishing with steel wool does this; maybe by smoothing the "bumps and dips" to remove the texture; or maybe by shining up the "dips" and leaving the texture invisible. Probably the former is correct.

I did some burnishing this AM on the J brackets (in later years support the muffler tips brackets). Does shine it up but the heavy rust pits remain behind but than...who's watching? An interesting affect.

A strut rod would seem to be a poor example for returning to a smooth shiny surface...the early ones I know about were forged, and therefore inherently rough. I don't know about the later ones; maybe they were fabricated from cold rolled rod and tubing..

Yeah the texture of the bead blast on a strut would seem to give it a natural feel but burnishing would undermine that affect. Bluing is an interesting approach but its a wash on process. Perhaps with some Prelube 6 afterward may provide the corrosion protection, momentarily anyway.

[Harmon C.]

Re: Restoration of a Bead Blast part to Natural Finish

It will be hard not to get a dedution on a forged part if the judge knows what a as forged part looks like when new. Natural finishes are hard to make correct so expect a deduction on a restored part and be happy if you don't get one as it will make your judging day less of a headache.
I have said a rusty chassis gets dedutions for rust and a restored chassis gets deductions for the wrong finsh or a coating of some kind to stop rust.
Have Fun Tom

[Chuck S.]

Re: Restoration of a Bead Blast part to Natural Finish

I did some burnishing this AM on the J brackets (in later years support the muffler tips brackets). Does shine it up but the heavy rust pits remain behind...

For that reason, perfect restoration of parts fabricated from rolled sheet can only be accomplished with new NOS parts, and that option has pretty much disappeared now. In a few cases, good reproductions will offer a new part alternative, but eagle-eyed judges are also likely to knick you for the differences from originals. Like Lyle says...you're danged if you do, and danged if you don't.

I concluded from my experience that bead blasting was a good cleaning option for painted parts, cast parts, hot-formed parts, or fasteners receiving phosphate coatings. If the parts or fasteners are zinc-plated or natural stamped steel, you'll preserve more of the original appearance by acid cleaning those parts.