Tub re-caulk

[Higgs Boson]

I am having a very long and annoying time removing the old caulk from my tub where it meets the tile wall. Somebody did a terrible job recaulking, a while back. I tried repeatedly to deal with the mold exteriorly with various mildewcides. Nothing worked, so I have now grasped the nettle, and day by day, am chipping away at this train wreck with various tools, mainly a razor blade in a straight holder. Ghastly business!

QUESTION: Since I don't ever want to go through this again, I want to clean/disinfect/whatever the area with the strongest and best mildewcide on the market before I recaulk.

Everybody has their own favorites. Is there a concensus?

TIA

[David Nebenzahl]

On 7/30/2010 4:58 PM Higgs Boson spake thus:

I think bleach does a dandy job, and is Available Everywhere. Anyone have a good reason *not* to use bleach? (Assuming you rinse it away completely before recaulking.)

[CraigT]

Concrobium Mold Control. They sell it in the paint dept. at Home Depot.

A heat gun would probably make it easier removing the old caulk.

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[larry moe 'n curly]

Use caulk remover, sold in tubes that look just like those for bathtub caulk. DAP makes it, and it's green goo. Lacquer thinner also works, but the fumes are strong. Only when all the old caulk is gone can you do a really good job of removing the mildew, such as with bleach or Lysol. Clean that off with alcohol or lacquer thinner before applying new caulk so it sticks better. BTW, bathtub caulk contains mildewcide.

[Higgs Boson]

OH,THANK YOU THANK YOU for all suggestions. I should have realized there might be such a product. I do have sort of a "heat gun" -- actually it's the tip of a soldering iron -- but I'll try that DAP stuff first. David thinks common bleach is as good a mildewcide as any. Other suggestions?

Also, how effective is the mildewcide in bathtub caulk (specifically silicone, which has been recommended by most (all?). IOW, do I need to add anything?

TIA

[Evan]

LOL... If you are using a soldering iron to try and de-caulk a tub, no wonder you are having troubles...

You need a HEAT GUN, which is basically an industrial strength hair dryer, which will provide more heat over a broader area than what a soldering iron will be able to put out...

You heat the old caulking and it will come out much easier with your razor scraper and other tools...

~~ Evan

[ransley]

Since mold is an issue its going to come back, it will come back because mold is airborn and everywhere, you just have the right environment for it to grow, you need more ventilation and for it to dry out, its pobably never drying fully between showers. Bleach is cheap and good to kill it then clean the residue, I had a bad place that stayed wet and kept a little bottle of bleach on a spray bottle to get any mold as t started. Cleaning the joint of soap residue is real important to get new caulk to bond to the tile, its hard to be sure its going to be clean.

[norminn]

I got a tip from a pro when I messed up caulking my tub enclosure. He told me to wipe the area with full strength bleach, let dry, before caulking. I did that and all was fine. I made sure there was no soap scum and I usually give a wipe with denatured alcohol before the bleach.

I have seen bad caulk jobs that turned gray from mildew behind the caulk, and those rough, gloppy caulk jobs that trap debris and water. I don't think it is as much the type of caulk as it is the preparation and form....shape the new caulk like a cove molding so it doesn't hold water. Scrubbing Bubbles is great for normal cleaning to get rid of soap scum.

["<<<]

I can't remember where I read this, but I was going through a similar situation and I read that bleach will remove most mold & mildew from the surface, but LYSOL is one of the few cleaners that will kill it off down deep. The nice thing about LYSOL is that it is a cleaner also, so it will get rid of contaminants other than mold which could interfere with a good caulk job. Bleach has no soaps or surfactants in it to break up grease & stuff.

[Ron]

On Jul 31, 9:59=A0am, " [e-mail]" wrote:.

Now how exactly are you supposed to run a bead that is "shaped" like this?

[norminn]

I forgot to mention that I use silicone caulk on tubs and sinks. As for cleaning "down deep", where might one clean for caulking where Lysol will reach and bleach won't? The issue is to have the surface to be caulked absolutely clean and free of scum, grease, mildew, moisture. Plain latex caulk with no silicone probably is one of the worst choices for wet areas. I've seen such horrible looking, mucked up caulk jobs that is isn't surprising they trap crud and grow stuff. Ventillation is important, too....I never leave the shower curtain closed after shower...I leave it open on both sides so air can circulate. Vent fan with timer for about 30 min afterward.

[norminn]

My bad...."concave" would be the intended shape....smoothed to the surface level on both sides of the arc. Wish I could draw a picture :o)

[Higgs Boson]

That's discouraging. Even if we beat out our brains cleaning, disinfecting, drying, etc. and sealing as best we can with silicone caulk -- it's STILL going to come back?

How is it going to get in?

[krw]

Yes, particularly if you insist on giving it a place to grow and its fav environment. When you re-caulk make sure everything is secure and smooth. If it does grow back it won't follow any water into the wall and it'll be easy to clean/kill (bleach works wonders, but be careful). Remove the constant source of water and it won't grow back.

Air. Spores are everywhere.

[norminn]

Mildew and mold spores float around in the air everywhere. When we got a timer on our bath fan, it helped cut down on mildew. We have a shower stall, tiled walls and floor, and it gets a little mildew in the corners but not enough to bother cleaning oftener than every couple of months. I regrouted the tile myself about 4-5 years ago, and could have used more muscle ... there are little dips in the grout and they seem to gather mildew first. Too old to do it over :o)

[Higgs Boson]

I looked up this stuff; it sounds iffy to me. Form an impervious layer and crush the poor little mold under it?

Dunno...

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[larry moe 'n curly]

When Consumer Reports tested several bathroom cleaners, several years ago, chlorine bleach was among the best products for killing mildrew, but it wasn't the best at keeping new mildrew from forming. That honor went to some other products, including Spic & Span (I don't know if they meant the powder or liquid), but they won't help you because they have to be rinsed off completely before caulking can be applied. I think bleach also has to be rinsed off, but I believe Lysol should be OK.

Bathtub caulk, whether it's latex (siliconized latex just contains up to 2% silicone oil) or silicone rubber, contains mildewcide. I think the only way to be sure that silicone rubber sealer does not contain mildewcide is to buy the kind made for repairing food processing equipment, including dishwashers. BTW, there are mildewcides you can buy as additives to paint, and they can keep fungus at bay for as much as a couple of years.

Why not just make everything in the bathroom black or dark green so mildrew isn't so noticable? :)

[Jim Elbrecht]

-snip-

Because then your cleaning is doubled if you ever use any soap . . . or water.

I had a dark bathroom once-- never again.

Jim

[Steve Barker]

It's not really a matter of favorites or what not. BLEACH kills mold and mildew period. But the secret is getting it dry back in there before you re-caulk. Or it'll just keep growing back there forever.

[aemeijers]

I'll second that. After multiple 24-hour and 48-hour waiting periods failed (not just mold, the damn caulk kept falling out), I finally abandoned the main bath for a full week and used the tiny stall shower and guest bath exclusively, and it finally stuck. I also scrubbed ALL the grout lines with bleach, and after recaulking the bathtub line and corners, painted them with that clear grout seal stuff. I then let the new caulk and seal set for another 48 hours before using the bath. So far, other than one tiny spot where the caulk pulled away, success. When I hit the lotto and build my dream house, the shower will have solid-surface walls and rounded epoxy (or whatever they make field joints out of) corners. I hate grout and caulk.