I wish I had some more productive input but all rust needs to be removed for it not to reappear.

Any and all rust auto-oxidises. If it is present it will spread on its own. It's still in an ambient environment, oxygen and water to an extent. When you see after being painted its coming from under the paint mostly. Not a result of surface treatment breaking down from weather etc.

Maybe someone has some other input or from the www. Just trying to help you be prepared.

 

With holes that small, you might get away with just using quick-set epoxy.

 

Use a rust converter. Hire dayexco to strip them with his laser.

Tom

 

Laser strip and epoxy primer.

 

Auto body filler / bondo is the most common way I've seen stuff like that repaired.
Get them clean and down to bare metal in the affected areas and repairs should last a long time.

 

I would have a talk with the customer, explain the depth of the problem. They are thinking a simple repaint, you are seeing the unpaintable parts. Make sure they want to pay for the full scope.

 

I agree that you need to be clear on the customer's expectations, what are they willing to pay for?

 

I'm thinking a flapper disk and / or random orbital sander to remove the rust on the easy to reach spots. Any suggestions on how to work on the inside corners?
I did explain to the customer that there was a whole lot of prep involved before the priming / painting could begin. I've already done three small $150 to $375 jobs for this guy and each time he's tipped me $100. He says the tips were because he's very happy with my work and professionalism compared to other maintenance people he's used in the past.
I'm not going to bid this job because there's no way to tell how many holes and cracks I'll have to fill. I believe he trusts me enough at this point to do the job on a cost plus basis. I think cost is secondary to quality at this complex. I just want to figure out the easiest way to remove the rust and fill the cracks.

 

He says the tips were because he's very happy with my work and professionalism compared to other maintenance people he's used in the past.

You want to continue the professionalism? Be very up front with the condition of the frames and tell him to expect the worst.

 

Multi tool with sanding head.
Velcro triangle paper 36 grit and up

3x18 belt sander and pad sander for more open areas.

Cheap lathe wood turning set, flats, rounds.
Really scrape into the corners.
Grinder to keep them sharp.

Can use the lathe tools with sand paper wrapped around for odd shapes.
There are multi tool odd shaped heads with sand paper but this maybe too much for them.

 

Thanks. I never would have thought of lathe tools. Great idea

 

Tape off the glass with a wide rubber tape to avoid scratching the glass. It is tempered ( I really hope it is) is you scratch it it may shatter.

Tom

 

Thanks. These windows go down to the floor, so by code I believe they have to be tempered.

 

And make sure you don't have carbide blades in anything around the glass. Especially carbide razor knife blades.

 

Lots of good ideas here. I’ll add that the multi tool sanding head works great for corners but I always turn the speed down a bit, it seems like it keeps the paint from melting onto the pad and gumming it up and the corners of the paper and pad last way longer. Also having extra pads handy is a good idea, the edges wear surprisingly fast.

Another thought, I just started using some of these pads on an angle grinder to clean some rust on my truck and they were surprisingly effective, I don’t know how they’d handled painted surfaces though. I think Wagner has a paint stripping tool with a similar pad.

Performax® 4-1/2" Coarse Paint & Rust Stripping Disc

The open-webbed, semi-flexible design of this wheel makes it easy to strip edges, contours and uneven surfaces without gouging. Silicon carbide grain is uniformly distributed throughout the wheel, allowing for aggressive removal of paint and rust.

www.menards.com

 

I've used this type of pad before and seem to remember it working very well, but wearing down kind of fast. I tested a spot using a flapper wheel on my grinder and it worked pretty well. I'll do a side by side comparison and see which works best and lasts the longest.

 

I had an old snowmobile and it started getting really rusty on the front skis, I used a rotary drill and a wire brush and then painted them with por 15, it turned the rust back into steel, and it looked beautiful for at least five years than I sold it.

It’s also UV sensitive so you would have to paint over it.

 

Thanks. I've never heard of that product. Unfortunately I can't seem to find it in any color other than black and these frames are very light colored so it may take too many coats to cover the black. I'll run an experiment.

 

Should be simple to go over the black use a spray on stain blocker by kills and then you can paint what other color you want

 

Eastwood company . They sell stuff for cars that convert rust and probably anything else you would need for metal restoration.

 

I have heard of stuff like that. What does it convert the rust to? Can’t convert it back to metal.

 

What your seeing is surface rust which can be cleaned up and repainted sure. But what your not seeing is the rust and rot on the back side of the frames which can only be fixed by replacement!! I have a gc who routinely stores the new frames outside and uncovered for months until needed. You can't fix this amount of blatant stupidity.

 

I guess it neutralizes it some how . I have no idea how it works but they say it does.
You can buy this stuff now from from tractor supply.
Eastwood Rust Encapsulating Paint

 

For small rust-through spots like you described, grind/strip the rust back to clean metal, treat it with a rust converter, then fill with an epoxy metal filler (like JB Weld or PC-7) instead of Bondo. Epoxy fillers bond stronger to steel, are easier to sand/shape, and hold up much better outdoors. After curing, sand smooth, prime with a rust-inhibiting metal primer, and finish with exterior-grade paint.