Project Finishes

[FlashBlind]

I'm looking for opinions on the various surface finishes for outdoor and shop steel projects. Assuming that most of us (Maybe just me..) don't have sandblasters and powder coating setups with ovens, is there a "Best" paint or finish. Right now I'm using a stringer wire wheel to prep then coating my mostly clean stuff with Zinc Rich Primer, then oil based enamel paint. The rusty stuff (I get oilfield pipe cheap) gets more time with a wire wheel followed by Rust Converter (Wal Mart or Gempler's) and oil based enamel. I'm still looking for a vendor for Ospho as a base coat and haven't tried one of those black abrasive coated "Scotchbrite" type grinding wheels for removal of mill scale and rust.
All opinions and experience welcome!

[cope]

For small projects I clean the surface and prime w/aeresol primer. I then use aeresol quick dry enamel (2 coats) for a finish. Used to be able to find a good brand of exterior paint called De-Rusto locally, but haven't seen it in several years. I sometimes use a laquer instead of enamel for quicker drying. Only exterior finish I have had a problem with is a brushed on enamel finish on a backyard gate and short fence. Peeling and fading after one year sucks!

[Franz]

First, stop spending so much time on wirebrushing etc, it only gets off the rust on the surface, and you'll be doing it all over in a few years. Go with electrolytic derusting and get down to clean iron. It's cheap and all you need is a tank and box of Arm & Hammer Washing Soda. You already have a battery charger.
Second, Ospho and similar products are way overpriced. So are Rust Converters from places like Gemplers. You can do a Tannic Acid conversion with teabags. Yu can buy Phosphoric acid. Either process is simple and CHEAP.

[Roger]

All this talk about rust is giving me flashbacks to my navy days and scores of man years chasing rust. With scrapers, chipping hammers, chains, and if lucky needle guns or deck crawlers. Red lead was primer of choice leading to leaded mud around piers.

Geat book about book about commisioning crew of WW2 distroyer excort crew taking ship from gulf coast ship yard, stopping in Hawaii on way to Philippines to take on Battle Ships. It said the ships were built of steel with mill scale that they removed with Phospheric Acid as they repainted ship inside and out (including voids) on way to battle.

Was thread on subject in news groups below a few months ago including acid sources & dilution, how to use results and more. Find with Google Groups search.
sci.engr.joining.welding & rec.crafts.metalworking

[FlashBlind]

Thanks for all of the replies.
Franz- I've used the electrolytic rust removal method for a while and it works great on smaller parts. I adapted a DIY version of the Outers "Foul Out" rifle barrel cleaner, using a 120 to 12v plug in adapter (99 cents at a thrift shop), poly bucket, scrap of stainless sheet as one of the electrodes, old battery charger clamp as the other. Attach the clamp the part to be cleaned, set it and the other electrode apart in the water filled bucket, add a shake of Baking Soda, plug in and leave overnight. I got the polarity right the first time and cannot recall which lead goes where, but it works every time. The solution is now a nasty mess, but still works fine. I'm trying to figure a way to attach/ clamp multiple parts in at the same time (More clamps?).
What is your method/ recipe for Tannic acid conversion? Bucket of water, steel and a box of tea bags/ or painting the surface with a concentrated tea wash?

[ChadRat]

Flashblind,
Take your stuff to Airborn Coatings on NW 39th street to have them powder coated. Talk to Steve. Tell him I told you about the place. They charge me $5 to $40 a piece depending on the size. Just drop your stuff off and they will blast it and coat it for you. Then you will have more time to weld.

[FlashBlind]

Thanks Chad, I remember you mentioning them and just found their address online last week. Wonder what they'd get for a truck headache rack? (My next project), I'll have to call today and find out.

[ryanevans]

try this stuff, my father in-law and his buddies swear by ithttp://www.parts123.com/PartFrame.as...ONID=0TT0RUNH2

[ChadRat]

Flashblind,
It is better to take your stuff so they can see it and give you a quote. I made some display stand frames when I talked to Steve about it he said $40 when he saw it in person he said $12.50
My porch swing cost $40. Ask him what colors they have coming up. If they have a color that is coming up and you can live with it then you can get your stuff back faster.

Chad

[andybaran]

All this talk about rust is giving me flashbacks to my navy days and scores of man years chasing rust. With scrapers, chipping hammers, chains, and if lucky needle guns or deck crawlers. Red lead was primer of choice leading to leaded mud around piers.

Roger,
You'd be happy to know that even with all the high-tech coatings today, nothing beats good ole Red Lead. I remember driving over the Coronado Bridge and looking down at all the red ships in the shipyards on 32nd St.
The Navy has even gone as far as to looking at sub-contracting out to civilian companys to take care of basic ships husbandry like chipping and grinding. Guess the Navy thinks the new breed of sailor needs more time to sit behind the computers...

Andy (BMCS/EOD/SW/AW)

*Still got my quals on a needle gun

[Franz]

Roger & Andy must be youngsters cause I ain't heard mention of a Holey Stone, a memory any deck ape would love to be able to forget.
The tea method isn't a whole lot different from Phosphoric acid treatment, but thanks to our GooBerMunt protectin us from everything, tea is a lot easier to come by than Phosphoric acid is these days. A few boxes of tea bags in 10 gallons of water, stirr like he!! every day and soak the part in the tea.
Another method is to get yourself some blackstrap molasses (comes dehydrated for cow food) and mix it up in water, and let the rusty part soak in it, rinsing thoroughly every couple days till all rust is gone. DRAWBACK to molasses is it only removes rust, and doesn't convert it like Phosphoric or Tannic acid processes do.
If you want to do electrolytic cleaning, use a solution of Sodium Silicate in water for the electrolyte, and run the process just like derusting. Pressure washing is recommended prior to immersion to minimize the amount of tank time.
BIG THING to remember about electrolytic derusting, DO NOT use stainless anodes cause they leave you with some real nasty hazmat products in the bottom of the tank. I'm about to start an experiment with sheet graphite for the anode, hopefully it will not hold the scum deposit like metal anodes do.
Between electrolytic and acid conversion, I haven't sandblasted anything in 5 years for rust removal. Electrolytic is definitely cheaper, and no **** dust.

[Roger]

I've been aboard a few big gun ships and tender with teak decks but never had the pleasure of holey stoning their decks. Last ship I was on you couldn't buy Red Lead but got all they needed from salvage.

[Jerry]

Hey Franz, I find this interesting and have never heard of electrolytic derusting. You say items needed are a tank ? what should tank be made of stainless or? Arm & hammer washing soda what would mix be to gallons of water. Then a battery charger connected to ? two leads that are suspended into tank without touching tank ?

How well does this work, how clean is metal etc.. Do you have a tank now and could you post picture Franz.

I have a cleaning station that I built from 16g. stainless steel that are 30"x 18" x 5" deep. There are four tanks the end ones are heated with a gas pipe under tank.

First tank is a mild acid which needs to be heated and will remove brazing flux and heat scale along with rust.

2nd and 3 rd tank are for rinsing.

4th tank is the Rust inhibitor and heated only because I need 5% solution if cold you need 15%.

I built this for I do some precision brazing on a rather picky part and had to do cleaning or possibly lose job. So I stepped up to the plate and made cutomer happy( Bottom line )

gotta go steel truck just pulled up

[Franz]

The best analogy I can make for electrolytic is to think of it as electroplating rust from where you don't want it to where you do want it.
Electrolytic is the absolute best method of rust removal because it gets all of the iron oxide off, including particles in the microporoscity of the steel.
The pereferred tank is poly, or any other plastic tank.
Stainless tanks become reactive in the process, and leave you with some real nasty hazmat as part of the reaction.
You can dip a whole rusty hit & miss engine into an electrolytic tank, and derust it, with NO damage to bearings, brass, pot metal or aluminum.
The process is self limiting, and will NOT damage good iron.
My setup is currently in the process of moving and testing sheet graphite as the anode, hoppefully, the graphite anodes will not require periodic cleaning as metal ones do. Old lawnmower blades work well as anodes, and they are free, but require cleaning about every 12 hours. When the anodes cover with crud, the process stops. Anodes must be equal in surface area to the object being derusted for maximum performence.
Electrolyte solution is about 1 heaping tablespoon per gallon of water. The solution will self heat when the process is working.
Solution needs to be replenished with water only.
Highly chlorinated water will require solution changes, as will derusting items that have been rusted in salt water.
IMMEDIATELY upon removing the item from the tank, clean the black slime off with dishwashing soap and water, or by pressure washing, if it drys, you won't get it off easy. We're still trying to figure out what the black slime is chemicly.
This is NOT an instant process, but it beats **** out of sandblasting.
SAFETY CONCERN~ The process outgasses HYDROGEN & OXYGEN, so do it in a well ventilated area, just as if you were charging a large battery, and NO SPARKS!
WARNING - check polarity by looking for small bubbles coming off the item being derusted. Reverse polarity will destroy what you are trying to clean.
Now, if I could just use the neighbor's pool for this process, I'd be happy.

[Roger]

The process is used on iron cannons and such salvaged form old ship wrecks. Don't know if they use same solution. For that use process can take years. Hopefully your steel isn't as bad.