Stubborn mold in caulk- deck joints (Pics) - The Hull Truth

Mc Key · 10-08-2008, 04:45 PM

How do you remove stubborn nasty mold from caulk joints? Used bleach, deck cleaner, pressure washer, compound, will not come out. looks like crap and i can't believe the deck is constructed this way as this mold is prone to grow and not leave these joints. all of these products made the caulk curl up from the joints of the deck so I had to be careful by not comprising the integrity of the caulk.

Anybody else have this issue, especially on 24 mckee? How do you remove/prevent?

thanks

Mildew remover is amazing for hatches and head areas...

B Dobz · 10-08-2008, 04:50 PM

mine gets like that and alittle bleach and a stiff brush and it comes right up.don`t know what to say with this one.

miike · 10-08-2008, 04:52 PM

I use acetone to clean sealant and it usually works well.

Mr. Demeanor · 10-08-2008, 07:16 PM

Try Tilex. For some reason silicone sealants seem to hold those stains better than polysulfide sealants (like 4200/5200). Tilex works better than bleach for some reason and its cheap so give it a try. May take multiple applications, it did on my from jump seat but it eventually worked.

35donzi · 10-08-2008, 07:39 PM

acetone

UaVaj · 10-08-2008, 08:46 PM

Becareful with acetone. Acetone it tough stuff and will takes a layer or two off. Don't get acetone on stuff you don't want to lose a layer - like on texture vinyl padding. It will melt the texture right off.

signmansez · 10-08-2008, 08:49 PM

I use the Outdoor Bleach by Clorox. It is thicker and seems to be more concentrated than the household. Pour it on and let it sit awhile, also works great on stained and moldy vinyl seats and cushions. Don't skimp and get the generic, use the Clorox brand.

Careful with Acetone, it is a solvent and solvents and anything plastic/poly generally do not mix well.

BAH · 10-08-2008, 11:15 PM

try x-14

R220Robalo · 10-09-2008, 04:28 AM

I have used "Marine Spray Nine", with a tooth brush for deck joints. Cleans and prevents mold for a while. I dont like the bleach and bleach products on new boat yet. LOL

SeaShot · 10-09-2008, 08:20 AM

I hate to say it, but the only way you are going to get that out is by scrapping it all out and replacing it with new. I have had the same problem with my boat and know others with the same issue. Tried almost everyting but the acetone, but would be carefull with that. There is no real way to fix other then cutting it out and replacing with new.

bamaboy473 · 10-09-2008, 08:51 AM

Scraping is all out is a huge job, of course, and one that'll have to be repeated regularly. After trying everything I could think of, I just got out the paintbrush, some oil-based white paint, rag and thinner to wipe excess. Caulk is perfectly white now. Here's a link to photobucket.
http://s450.photobucket.com/albums/qq223/bamaboy473/

Mc Key · 10-09-2008, 09:44 AM

thanks for advice. will try again this weekend and posts results. cutting out and replacing is a huge job that i am not willing to do now. maybe years down the road, before putting up for sale, but it has to be "perfect" for the water to travel to the sculpers.

miike · 10-09-2008, 09:50 AM

try acetone on a small area if you are worried about it. dab some into a cloth and then put your finger behind it and rub the sealant with the cloth. acetone tends to dry out the sealant but its better a little dry than dirty in my opinion. if you get acetone anywhere wax over it because the acetone will remove wax.

btw tilex = bleach and water

bamaboy473 · 10-09-2008, 10:04 AM

Let me know if acetone actually works for you because I tried paint thinner, then GooGone, then moved up to Zylol (similar to acetone). There was a lot of elbow grease expended for marginal results.

Painting the joints around the rub rail took about 10 minutes and looks better than factory. I expect that the paint being oil-based and a gloss finish will allow for easy cleaning, too.

leebert · 10-09-2008, 10:35 AM

Quote:

BAH - 10/8/2008 10:15 PM

try x-14

Ditto on the X-14. Worked great on my boat.

LB

Cooper · 10-09-2008, 12:03 PM

I have some areas like that on my boat. I'm going to remove the white caulk and replace with black so the inevitable mold won't as visible.

1NO REGRETS · 10-09-2008, 12:32 PM

Use pool chlorine and make sure it stays for AT LEAST 20 minutes.DO IT IN BRIGHT SUNLIGHT.That will work.Mold needs two things water and air,when it is gone go over it with a new layer and be sure it has a moldicide in it...........before going over wipe with acetone to get a good bond.

Do not use caulk use a marine sealant, not 5200 but the expensive stuff will not allow mold in it, just on it.If it is on it it comes off with bleach .If its in or under it you need to bury it in bleach or pool chlorine for extened amounts of time. cover in plastic if necessary to get rid of air.

ALSO KEEP IN MIND YOUR HATCHES ARE NOT ALLOWING WATER TO RUN OFF OF THE SEAL, BUILD IT UP OR RAISE THE ANGLE OF THE BOAT TO DRAIN OFF WATER INSTEAD OF LETTING IT SIT ON THE SEALS!!

Jonafare · 10-09-2008, 02:50 PM

Put soft scrub with bleach on it, let it set 20 minutes, rinse it off. Mold will be gone.

Troutman561 · 10-09-2008, 02:56 PM

A side note from the main question..

With that mildew remover, did you have to scrub, or just spray and rinse?

inaforty · 10-09-2008, 02:57 PM

Quote:

Jonafare - 10/9/2008 1:50 PM

Put soft scrub with bleach on it, let it set 20 minutes, rinse it off. Mold will be gone.