My bath tub was really rusted. I asked my plumber for advice and he said it would be several thousand dollars to replace the tub, and our old tub looks like a custom size. He suggested I repair it and this is the method he explained.
I started with a fairly rusted bath tub. This rusted spot is in an area with less water then the bottom and does not support any weight.
DO NOT try this repair for the bottom of the tub or near the drain!
This was really bad. The rust started to spread to the left top area and metal started peeling off.
I removed the drain knob by removing the 2 screws. This was also heavily rusted.
I removed any loose pieces and used a file to remove more loose pieces. I want to leave behind only good structure.
this is the remaining good bath tub.
I design the opening in metal to help support the body filler in place.
I removed the circle (this is where the drain lever goes) This is where there will be no body filler.
I bent some copper wire strands to hold the mesh in place.
I added a little liquid nails to hold it for the body filler. I leave it to dry 24 hours.
Now the copper wires are not needed.
Masking tape is added around to protect the tub.
More masking tape is added to the inside to plug the pipe.
Here is the body filler and the hardener (you mix them to activate the cure process).
I mix it on a paper plate and apply a little at a time.
1st coat done. Thin even coats are better then a fat coat you have to sand. I let it dry for 24 hours.
These are the sanding tools for body filler.
I used those sanding tools to remove some body filler material to even the surface. There are some spots that are not high enough, so I added another coat. I also fixed the hole shape better. I let it dry 24 hours and sanded.
Just a little more sanding and it will be ready for paint.
I had to shower so I made a quick cover in plastic food wrap and masking tape.
After a bit more sanding, I masked off the bath tub and covered in paper.
This is the first coat of paint. I used white appliance paint (but was only water resistant) . I let the coat dry and painted another coat on.
update 11-30-2016 – The paint is still holding up 3 years later… Lets see how long before I need to paint on another coat.
You can see the area where the masking tape is, but only when looking very closely. I am surprised how close the white paint is to my tub!
The repair is done and looks great!