PAINTING galvanized pipe – how to?
I have 800′ of 2.5″ galvanized pipes to paint black. We are using them for area light poles in lieu of that thin steel tubing.
In The Good Ole Days I could buy a product called GalviGrip that really worked on fresh galvi surfaces. Painted my anchors white with it for years. But that was then and this is now.
What works for you in cleaning off the oil film, priming and then painting??
Any tips on a production paint yard setup? We will have a bin in the back 40 of this complex. I don’t think spray is a good career move, but rollers…not a problem. Need some system of holding the pipes for painting on all sides and drying.
The ToolBear
“Never met a man who couldn’t teach me something.” Anon.
Replies
I used white vinegar to wipe down the conduit I painted. Primer, don't remember. Top coat, good enamel. This has held up well for 16 years inside.
A great place for Information, Comraderie, and a sucker punch.
Remodeling Contractor just outside the Glass City.
http://www.quittintime.com/
Hi TB,
I don't have a specific suggestion for degreasing, probably a strong detergent of some sort. Is TSP still allowed?. (How about a drum of mineral spirits in the dark of night?).
Mild acid will etch the zinc to give your paint a mechanical bond. 5% Phosphoric is the best IIRC from my paint factory days. With solvent based paints you could put phosphoric in the paint itself, but not with water borne - raise the pH and they fall apart in the can. Don't wait too long after etching to paint. Once the zinc oxidizes, you get adhesion problems.
Why not hang the sections from 'J'hooks or better yet, attach a 2' length of cheap chain to the end of an 18"-long 2x2 and hang the other end of the chain from a beam. With one of these contraptions at each end of the pipe, you can stick the 2x2 into the end of pipe and the weight will hold it. All surfaces of pipe will be available to paint with no marring.
To replace pipe, lift the end, pull out 2x2, insert in next pipe section and so on.
I think you can do the work with an airless with narrow fan and low pressure. Overspray should not be bad unless it is windy.
I don't have a specific suggestion for degreasing, probably a strong detergent of some sort. Is TSP still allowed?. (How about a drum of mineral spirits in the dark of night?).
Sherwin Williams notes that mineral spirits will leave a thin residue that leads to "adhesion failure of the paint film".
They suggest a water-based degreaser such as "ProClean Professional Prep Wash Cleaner." I suspect they sell ProClean. TSP???
The zinc reacts with the alykd binder to create a soap film. (SW)
The ToolBear
"Never met a man who couldn't teach me something." Anon.
Whatever you do....don't leave em hanging up in the garage!!!!!!
and if you do....
LOCK the door!!!!
http://forums.taunton.com/tp-breaktime/messages/?msg=81792.1
painters...!%$&()*$$$
"The zinc reacts with the alykd binder to create a soap film. (SW)"What alkyd binder? TSP is trisodium phosphate - nothing alkyd about that. How could zinc react with anything to make a soap film? Soap is fatty acid reacted with a base of some sort - NaOH, KOH or whatever.They don't hire organic chemists to work the counter at SW or any other paint store.
BruceT
That zinc and alykd making soap thought was from Sherwin Williams web site.The ToolBear
"Never met a man who couldn't teach me something." Anon.
"That zinc and alykd making soap thought was from Sherwin Williams web site."I don't know where on the SW website you found that answer. There used to be inorganic zinc-rich primers in alkyd binder. Following is a link to soap chemistry. Not made of zinc/alkyd.http://www.chandlerssoaps.com/chemistry-of-soap.htmlBruceT
Don't know about paint, but i just bought a couple of 2.5" ridgid conduit - man are those hard to come by! As for how to hold them, try this:
View Image
Two vertical boards (They can be like a 2x8 with the narrow edge fastened to the wall to keep them upright), each with 1 1/8" holes bored into them. One of them has 8" long by 1" diameter dowel fastened into those holes, the other side you have dowels you can slide in by hand. You wrestle each pipe into the dowel studded side, then level it to the other side, fit your dowel into the pipe - match it to the hole then fit the dowel into the hole. The dowel will wedge in place and you are free to paint the outside unobstructed.
Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Cypress, eh?
Walter's Electric in HB? (off Bolsa) shows 6000' of the stuff in stock, but I bought the last stick in that store. They will move some over.
We found that Industrial Metal Supply in Irvine would sell it for 3.11/ft for our 800' quantity in 20' lengths. Walter's got $54 for their stick of 10' 'cause I needed one today. Now I have to clean it.
Need to check the fence suppliers as there is a sked 20 and sked 40 in their world with a 3" OD - which would be just fine for 3" dia light heads. The magic word is "Terminal Post."The ToolBear
"Never met a man who couldn't teach me something." Anon.
Funny, I thought I got Walters last two!
Rebuilding my home in Cypress, CA
Also a CRX fanatic!
edit: I just reread that line... for some reason it doesn't quite sound right.
Edited 11/21/2006 12:13 am ET by xxPaulCPxx
I'd call a good auto body shop. They have all kinds of cleaners/primers for steel, along with the skill and spray setups to do a superior job. If you don't clean and pickle it right, it'll sure look crappy when the paint starts flaking off.
Flakey paint we don't need. The current stuff lifts when you apply blue tape.
(Not our work.)The ToolBear
"Never met a man who couldn't teach me something." Anon.
My vote would go to an acid etching zinc chromate primer. The following is sold for use on aircraft on bare or plated metal:
http://www.aircraftspruce.com/catalog/cspages/ptiacidetchprimer.php
Beer was created so carpenters wouldn't rule the world.
I asked this very question this summer.
My project was a bit more modest...some hand rails for our front steps.
I ended up letting them 'weather' for a few weeks outside while also spraying them down a few times with vinegar and scrubbing them down with steel wool.
After a few weeks, the sheen was gone and it was slightly pitted. I then gave it a coat of gavlanizing primer and then water-based black spray paint.
It has held up thus far.
That said, these are just hand railings and I can easily spot-touch any scrapes down the road. For lightpoles, I'd consider doing what other's suggested to me: get it powder coated.
If you really want theses done right and will last in an outdoor environmnet get them powder coated.
But I don't know if you can find any shop that can handle that long a piece.
I've had consistently poor adhesion to galv. steel with any of the alkyd or water based coatings I've tried, regardless of surface prep. or product used.
I've used primers specifically sold for galv. steel, tried the vinegar thing, waited for weathering to dull the surface, degreased with Xylol, Toluene, and even Acetone. I've sanded lightly by hand and through it all I've watched my paints start to flake off in a few years regardless of how much effort I seemed to put in.
After reading the applications guide for Rustoleum high performance coatings, I tried a suggestion to degrease 1st with a volatile solvent wash and followed it up with a Brush-Off sand blasting at reduced pressure. Then I used a 2-part epoxy sprayed on with a conventional spray gun (pressure feed) and can happily report that after 12 yrs. of continuous outside exposure on a west facing side of my shed, the 2" steel conduit that feeds my electrical service has not flaked or peeled at all!
The sandblasting was a bit tricky; dwell too long on a spot and you run the risk of stripping the galv. off. I found that just a second or two of "brushing" the surface with the blast from a distance of 1'-2' dulled the galv. without removing it. Moving the blast gun back from the surface even more gives you much more control.
Depending on what sort of gloss retention you need, I would think that a 2-part polyurethane would give you the very best surface over the long haul, followed by the epoxy (which lost its gloss in 3 yrs. for me).
Earlier posters with suggestions on how to rack the pipes for painting, and speaking to Automotive painters gave great advice, I think. The North American Automotive Industries had much trouble early on when they 1st began to produce and paint body panels from galv. steel. A reputable body shop of more than a few years in business should be able to point you in the right direction as they would have a reputation at stake if their paint jobs failed prematurely. Perhaps a local dealership's body shop would have the inside info. on what to do for prep. & painting right from the factory; many new vehicles use galvanized body panels now.
Electrostatic spraying would be my 1st choice if I had access to such a gun and price were no object, the "wrap" you get around curved metal surfaces and corners is almost unbelievable if you've only been used to a conventional or airless spray gun as I had. I wouldn't discount a plain old roller though, if the finish didn't need to be glass smooth , however. A roller is very fast compared to brushing and has very little waste compared to spraying. It is also very cost effective (read cheap here) as cleanup time and material expense can be nil compared to the 30 min. and about a quart of solvent I typically use to to clean the gun and hoses on my old conventional pressure-feed DeVilbiss JGV outfit.
Let us know how you did when the job is done. I for one would appreciate knowing what steps you took and the results you get, good bad or indifferent.
Never, ever too old or knowledgeable to learn from others,
STAINLESS
Good luck
These will be outdoor area lighting poles, so don't look for any mirror finishes. It will be rather low tech - yes - rollers are looking good. However, we want the paint to stick.
Just read one label telling me not to use TSP. So, what to degrease with?The ToolBear
"Never met a man who couldn't teach me something." Anon.