Prepping & Painting a steel rail to prevent rust

[rnbrown]

Before beginning work on a cncrouterparts style 8' x 4' gantry 8020 router, i'd like to square a way a few things that will insure a long life out of it. The largest issue so far is how to prevent the rails from oxidizing over its life span. This router will be subjected to a South Carolina environment with no temperature or humidity control in its building. This means some really hot summers with near 100% humidity on a lot of occasions. Also, the winters get rather brisk (18°F lows in january/feb)

I think the most reliable way to maintain the rails is to paint over the top and bottom portions of the rail that the linear carriages do not ride on (the middle parts of the rail). I was wondering if others have done this and how they prep a 8-9' rail for paint, and how many coats they used. So i'm asking some information from the more experience about how they prepped their rails for paint.

Currently, i'm thinking a good scrub with steel wool and some cleaner to remove the oils and current oxidation, let dry, then tape off the sides and 1/4" of the top/bottom and go at it with some primer, and then paint colors of choice.

All help and input is appreciated, thanks in advanced.

[ahren]

You've pretty much got it -- CarveOne did the same thing in his uber-build log some time ago. Rustoleum hammered finish is a popular one for the non-working portion of the rails.

Best regards,

Ahren
CNCRouterParts

[heavycnc]

I'd use a two part epoxy. Marine grade would be the best choice. This is the same stuff used on boats and salt water is a harsh environment for steel of any kind.

[CarveOne]

My procedure is to clean off any oils and dirt from the rails with a shop rag and acetone or lacquer thinner. Outdoors.

Then mask off the long edges using 1" wide green or tan masking tape (blue painters tape is not tacky enough to stay stuck for long). Center the tape over the flat edge and roll it over the corners and down the sides while keeping the tape centered on the edge.

Then spray paint the rails with some flavor of Rustoleum or other spray paint in a can. I started with hammered silver metallic on my large machine, but have since been using the textured silver metallic for more sparkle. There are a lot of choices available. I want to see someone sandblast some shadow flames in the rails and paint it with a candy color.

For rust protection on the unpainted edges where the bearing carriages roll, coat occasionally with Boeshield or other surface rust protection products. I have been using Eagle One pure carnuba automobile wax with good results. Just it buff off after applying it. I put on three initial coats, then re-coat every few months when it needs it.

CarveOne

[heavycnc]

I've used the Rustoleum hammered finish and after a few months outdoors, the hammered finish fades off leaving you with a one tone color. A marine grade epoxy paint is a much harder finish. The difference between the two products is day and night.

[jscavitto]

My crs was coated in some type of grease to clean I used wd40 then simple green then denatured alcohol.

The blue painters tape worked fine for me.

I used a primer and allowed that to dry for 48 hours then two coats of Rustoleum Enamel Aluminum (not hammer tone).

The uncoated stuff I wipe down every now and then with a lubricant called Tri-Flow with Teflon.

[slowswim]

are you guys talking about painting the cold rolled steel rails for the linear carriages? i was wondering the same thing and just want to be sure i'm following this correctly.

[jscavitto]

yes painting the part that the carriages don't ride on

[felderfan]

Hi
Over the years i have attempted painting steel using your standard primers & topcoats with some success, but the best method by far is to clean down to bright metal clean with Acetone or Cellulose thinners and use a two pack acid etch primer, once that is dry(maximum 24 hour open time) use any suitable paint system. I did some touch up on a combination machine i refurbished about 10 year ago and used etch primer on some of the tinwork, never got round to overpainting it and it still shows no signs of rusting despite having to constantly clean rust from the machine tables.
This stuff can be a bit difficult to get hold of now because of environmental grounds(fumes would kill a horse) as it contains Chromate, but used with care its the dogs.
Regards
Mike

[mcphill]

Bead blast then powder coat. Can't get better than that!

[beermkr]

There is a product called Jasco Metal prep at Lowes that I would swear by. A few years back I built a work platform for my brewery and used it on the bare metal. I painted it with exterior enamel paint and it has been rust free for years now. The platform gets subjected to LOTS of water, chemicals, etc over its life.

Coolest part was rolling the curves on a 150 year old cannon wheel roller

[johngalt47]

I feel you need to scuff the metal to give the paint some bite to adhear to. this is how car paint is applied you can't get a worse envirioment than that.