View Full Version : Porcelain surface eaten up in bathtub...

10-12-2011, 04:09 PM
Hi there,

I have a good old cast iron tub. Recently I notice there is a trail of the porcelain/enamel surface eaten up -- perhaps by chemical?

It's right below the tub shower door.

I think that trail line goes 1/16" under the rest of the tub surface.


The surface at the bottom of the tub is pretty rough already--probably from harsh cleaners roughing up the surface over the years.

This trail however is quite obvious. I wonder how to repair this surface section (repair that lasts) so it's flush again w/ rest of the surface or not noticeable again.

Or it is too eaten up to be fixed? Time to get a new bathtub?

Thx... .

PS: Actually, is this an enamel or porcelain surface?

10-12-2011, 05:33 PM
It is a "fused" porcelain enamel. The ONLY good repair is one done by a professional refinisher, usually found in the Yellow Pages under "Plumbing fixture repairs" or "Fiberglass repair" (even though yours is cast iron". An Internet search for "Todd's fiberglass repair" in AZ MIGHT put you in touch with a similar company in your area.

10-12-2011, 07:26 PM
Thx hj.

Are you suggesting to refinish the whole tub's surface? Or just spot treat that problem?

(Have no idea what companies normally offer)

If it's refinishing whole tub, I wonder what the cost would be -- compared to a replacement of the tub.

In particular, how long would it last (practically speaking... )?

I am actually redoing the tile area above the tub now, so the tile areas are relatively open at this moment. So if the refinishing cost is similar or not a lot less than bath tub replacement, I might want to go the replacement route.

As I wonder how long a refinishing (whole tub) would last (good 14+ years?)... . Heard about unpleasant stories of refinishing jobs,

so wonder if anyone knows which kind of refinishing product/paint material would be more reliable/long lasting, like acrylic resins/urethane/polyurethane based materials, etc.


10-13-2011, 02:04 PM
A refinish job is highly unlikely to last anywhere near as long as the original factory finish. Now, there are places that can take the tub and replicate the original finish, but that is generally reserved for some archtecturally correct restoration and involves bead blasting the surface removing the finish, then applying a new one including firing it in a furnace. The epoxy finishes can last awhile, but the quality depends entirely on the skill and materials used by the craftsman.

Gary Swart
10-13-2011, 03:09 PM
I've never had this problem, so this is just my impression of what seems to me to be something to consider. If you desire to salvage the old tub, you will have to remove it and take it to the repair facility. Removing a cast iron tub is never easy, and often is only done by demolishing the tub. But, assuming you could get it out of the bathroom in one piece and back in when the job was completed, This would not be an inexpensive job especially if done right by a real professional. I would wonder if it might not be a better plan to replace the tub with a new one. Just an opinion that is not based on solid data.

10-13-2011, 03:37 PM
Given the understanding that refinishing isn't going to last as long as real porcelain prepared in the furnace,

is perhaps 10 years of life expectancy for a refinished surface practically possible (assuming no harsh chemicals/abuse)? Or that's still too much to expect?

Tub Refinisher
10-29-2011, 04:12 PM
While a refinishing job won't last as long as the original, it should be a viable alternative for you if you keep in mind a few things. One, the major portion of the cost of replacement is busting up the old tub, and replacing the tile around it, and the plumbing as well. Since the new one won't occupy the same footprint, everything will need to be re-worked. Two, it should last average of 8 - 10 years, with the possibility of as much as 20 years, depending on how often it's used, and how well it's taken care of.

Contractors in my part of the world generally charge around $1500 for the labor alone, add to that the cost of the tub itself, tiles, plumbing, etc., and it can really add up. Compare that to a good refinishing job at around $350 to $400. I emphasize good because as has been previously mentioned, there are some substandard jobs out there. For example, if anyone says they're going to use epoxy, they don't belong in the business. Epoxy is one of the worst materials that can be used to refinish a tub. It has very poor color retention, it's very brittle, stinks for a long time, and take a long time to cure.

If you're going to get it refinished, you need to do your homework and find someone who does a professional job. Find out what materials they use, and why. Ask if they acid etch, use a primer, and how many coats they spray, and what their warranty covers. Many companies today are cutting corners to save a few dollars. Ask if they remove the caulk and install new caulk, after they spray, not before. Ask if they need to buff out the tub after they spray - this could indicate a dry spray effect that leaves a rough finish. Make sure they come out and look at your tub and don't just quote on the phone, since you have damage. I quote many jobs on the phone, but when there's damage involved, I don't want any surprises for me or the customer. Make sure they plan on filling in the etched areas and not just spray over them. You want to make sure you get a quality job. Don't expect to pick someone off of Craigslist and a cheap price and get a good job done. Those are the guys that give my industry a bad name. Find out not just how long they've been in business, but who is going to spray your tub and how long have they been in business. The company could have a 20 year history and send out someone they just trained last week.

If I can help with any questions, email me at permaglaze at verizon dot net.

10-29-2011, 04:34 PM
In my experience....for what it is worth....ten years is pushing the envelope for the life expectancy of a refinish-in-place job, whereas the new tile job has an easy 30 year expectancy. You really want to match up that tile with a new tub.

10-30-2011, 01:38 PM
A good refinish, or patch, which is what you need, will last a long, long time. It would cost more to refinish the entire tub, but it would cost LESS than the new tub, AND the wall repairs which would also be needed.