Everything is rusting!

[Gundog48]

I normally only forge blades which I always finish with simple oil and a polish, but recently I've been getting into decorative work and I'm having some serious rust issues. I think part of it may come from when I quench some pieces in brine, but most are not and I keep my brine bath stored outside! Up until now I've always finished my products by wire brushing then spraying with a few coats of clear coat or sometimes painted. All my clear coated pieces always rust through. I always thought it was because I wasn't cleaning them enough, the most recent pieces I did I wire brushed to almost a polish, then cleaned the whole thing with isopropyl to make sure it was entirely clean of everything. Gave it a coat, waited, gave it another. About a week later the metal had turned from a polish to a darker metal finish and it was starting to rust in places.I did a piece cleaned in the same way, two coats of red oxide primer, then a few coats of black, left it to cure overnight, when I came back the next day the paint had flaked off in places down to bare metal having never been touched, and I knew that primer was a good solid coat!

 

Now, I've decided that laquers and paints are not the right way to be doing this- too much hassle! I'm looking to switch to waxes instead, but I'm concerned I'll still have this problem.Having never used wax before, what do you normally do prior to applying the wax- do you wire brush it to remove the scale then apply it while the metal is warm? I plan on mixing some renaissance wax for my shiny stuff, and I've heard of a beeswax-gun blue mixture which I've seen being applied cold. 

 

The real question is though, will switching to wax solve my problem? I'm still certain that it's rusting from underneath the coats of whatever I put on it, I don't think it's rusting through the clear coat, but underneath it. I can research the use and benefits of different types of wax myself, but I'm struggling to find anything specifically concerning this problem!

[Chinobi]

It sounds like they are not fully dry and you are encapsulating the remaining moisture underneath the paint job. Surface dry won't cut it :) what do you do between the alcohol and the primer?
You might have more success if you heat the piece before finishing to drive off moisture still trapped in the scratches of the surface. Wax is best applied warm it seems as well. I defer to those with more experience for more specific paint and primer troubleshooting.

[rthibeau]

hmmmm.........you tried using purple paint????   Just askin'..... :ph34r:

[ianinsa]

hmmmm.........you tried using purple paint????   Just askin'..... :ph34r:

 

Brown?... you mean...wo'nt see the rust!

 

Seriously though, Gundog   moisture is key to rust! Also check your imediate environment for salt, acids and/or alkali products these get airborne and create havoc. I had a problem a few years ago when a bag of fertiliser had been left in a store in the workshop(do'nt ask)  and all the tools in that storeroom aged(rusted) very rapidly(polite description)  

 

Ian

[Gundog48]

Thanks for the tips guys! I've been doing everything to clean it an assumed some wiping and using the wire wheel would remove any moisture, but I never considered about what is hiding in the tiny cracks and crevices! I think a wax applied hot would be my best bet- I take it you only get it mildly warm, not enough to create scale?

[yahoo2]

I think it needs to be a couple of steps, preferably before any rust gets established on the surface.

 

I would dunk them in a warm  (below boiling point) degreasing solution for 5 minutes, make sure the detergent is not salt based. This gets rid of the salts and water absorbing oils on the metal.

 

Rinse the part in running water for a minute or so to remove the detergent.

 

Then you need a paraffin based solvent to displace the water out of the tiny pits in the metals surface. Mineral turpentine (mineral spirits, paint thinner) or a light kerosene is what you are after (non-deodorized works best)

 

Try a wash of mineral turps mixed with a bit of your  wax or oil, dipping for a couple of minutes works best but if its too big for that, liberal application with a paint brush in all the joins and crevices is OK  then let it dry.

The solvent should do its job and dewater the metal surface then evaporate leaving the heavier sealer behind in its place.

Now it is ready for a wipe with a paper towel or finishing coat of oil, wax, rust inhibitor or whatever!

 

P.S. alcohol or lacquer thinners (methylated spirits or acetone) wont do anything to remove water.

[Gundog48]

I've been struggling with turp for a while, only today realised it's what we call white spirit in the UK and is super cheap! So, if I was looking to get a shiny wire brushed finish, I should finish forging it, clean it up to the wire wheel to make it as shiny as I want it, wipe it down thoroughly with turp then apply a turp-wax mixture with a brush and leave it on for a while before wiping it down and finishing with a beeswax, turp and linseed wax?

 

I'm trying to avoid the first step as it won't be possible to have a decreasing bath big enough for some of the stuff that I do in my tiny shop! 

 

Thanks very much for your comments, this is the one side of things I'm rather unsure of and everything said here has been very enlightening!

[Robert Yates]

What most folks do not know about Kent England is it is cold and wet a lot ,you know that as well as I do ,Gundog. and paint does not stick to that and will rust every time . as stated you are going to have to heat it up to get the moisture out /off of your steel Brother .

 

Sam

[yahoo2]

My workshop is not clean enough to get away without using a degreasing solution, I really need a "clean zone" where I can put stuff away from the grime.

Something sold as "wax and grease remover" will be a mixture of white spirit and naphtha, that's as good as any to blend the linseed and wax with.  When its all wiped back and dried the end result should not be tacky or oily. A tacky surface attracts dust, dust holds water, water leads to rust. Heat will certainly reduce the moisture but on a humid day its an uphill battle.

 

If you are looking for some serious rust inhibitor for bare machined metal a product like corrosionX is the best I have come across, its about the only thing that will stop unblued machined rifle barrels from showing etched fingerprints  and blemishes. I use it on my machining and measuring equipment.

[PaperPatched]

You may want to reserve using brine for only certain classes of work.  In the paint world not even sandblasting to the brightest industrial standards will remove all the salt that imbeds in the steel of bridges in our harsh New England winters,  So, when re-paint time comes the painting specifications will usually call for some special wash after sandblasting to try to remove the chloride ions that remain lodged in the pores of the steel after sandblasting.  If the chloride is painted over it will form "osmotic blisters" (draws some moisture right through the paint film and starts corroding, eventually causing the paint to flake off the blister). I only deal with residential and light commercial paints at work and my auto hobby caused me to do some reading on dealing with rust on car and truck frames. There are some very good DTM (direct to metal-no primer) paints on the market. I have one on our clothesline posts that my wife and my mother in law applied the year before my daughter was born. So I can date the paint job to 1985. In the last couple of years a small amount of rust has formed where the cross bar pipe was drilled for eyebolts.  The rest of the paint is fine.  The only complication is that that paint is no longer made, and has had two replacements, the last only a couple of years ago, so not much history yet. I painted the frame and underside of my truck last year with the latest version. I hope it is as good as in the past. If we have a member trained in industrial painting we my be able to get some more information; and are very likely to be teased with some products that we can't obtain.

 

Also, to clear up something in a previous post: mineral spirits (white spirits in the UK) is distilled for crude oil and has a somewhat higher solvent ability than turpentine.  Turpentine is distilled from the sap of pine trees.  I much prefer the odor of turpentine, and it is an ingredient in some older formulas for paints and polishes, but it is of lower solvent ability (doesn't clean paint brushes as well) and dries considerably slower, and can leave somewhat of an oily residue.  If you have any expensive natural bristle brushes turpentine is less harsh and will lengthen their lifespan versus cleaning in mineral spirits.

[arkie]

I was reading up on using spray finishes such as laquer and varnish on bare metal.  Heat before treatment is one deterrent, but the article described why the sprays don't always work.  Seems as though when the propellant in a spray can (air, nitrogen, butane/propane, etc.) sprays the liquid out, the sudden cooling of the gas due to expansion leaves a molecular layer of condensation moisture as the finish is applied.  This does not always yield a rust-proof finish.  Slight heating of the metal surface beforehand can help, but not always.