How Do You Clean Moldy & Dirty Silicone Caulking?

RadioguyJ

Well-known member
Member
Joined
Jul 16, 2002
RO Number
9357
Messages
533
Most of the silicone caulking on my boat near the rubrail and other critical joints has become dark with mold spots and dirt. I know this silicone is not too strong and can be peeled away. Is there a way to clean this stuff up, or will I have to remove it all and re-do it?

I am hoping it can be cleaned. I'm not too keen of removing all of the old stuff.
 
I have the same problem Jason. Have tried pretty much everything but I'm affraid, in my case, it has to come off. It looks like the mold is underneath the silicone (clear). I'm going to recaulk the joints with 4200. Looks nicer and lasts longer. Wet your finger with some mineral spirits and smooth out the 4200. Leaves a nice radius. Some spots where I removed the silicone I had to clean up with some acetone to get rid of the residue from the silicone.
 
quote:

Originally posted by RadioguyJ

....other critical joints has become dark with mold spots and dirt...




I have the same problem- it really upsets me - can't seem to get rid of it - I used a clorx bleech pen last year on a few spots which made it better for a short tim but the spots come back
Maybe Cruisers has a answer
 
Rick: how will you get the 4200 to stick to residual silicone???
 
The only way I've been able to clean this on the boat (or in the tub, for that matter) is to remove the old and re-caulk. Did you guys know that red jello really stains silicone caulk?
 
quote:

Originally posted by pdecat

Rick: how will you get the 4200 to stick to residual silicone???





Hey Bruce

I cleaned it as best I could with the acetone and roughed it up a little bit with some 1200 wet sandpaper. I think the silicone leaves something of itself behind right into the gelcoat and the only thing that'll stick is more silicone. (somebody rebedded my side windows with silicone [:-crazy] ) We did a buddy's Bayliner 3888 around the rubrail last year with the 4200. It stuck all last year, haven't looked at it yet this year to see if it's still there or not. I'll let you know.
 
Try using either Spray Nine or Bleach, with a toothbrush. Let the solution sit for awhile and rinse.

This has worked for me in the past.
 
quote:

Originally posted by blouderback

The only way I've been able to clean this on the boat (or in the tub, for that matter) is to remove the old and re-caulk. Did you guys know that red jello really stains silicone caulk?






I believe you Bob.....but does Jello stain a prop?!! :)
 
find some "goof-off", it works good. acetone works too but can remove it also... but at least the area will be clean then lol
 
Same problem here...I had to remove all the old silicone and wiped the area with acetone and reapply the silicone...Be sure to tape both sides of the area to be re-siliconed..It makes for a cleaner job..
 
Goof Off, as I recall, is just a proprietory form of Xylene. I believe that is true of VC-17 thinner as well.
 
Gasoline, paint thinner etc. will soften and wrinkle up the silicone so you can wipe it off. Alcohol will not. A trick to get a smooth bead on application of silicone is to have alcohol in a spray bottle then once the caulk bead is down spray it with the alcohol then do the finger wipe. A little practice and you're a pro!
 
quote:

Originally posted by Reel Antsy

quote:

Originally posted by blouderback

The only way I've been able to clean this on the boat (or in the tub, for that matter) is to remove the old and re-caulk. Did you guys know that red jello really stains silicone caulk?






I believe you Bob.....but does Jello stain a prop?!! :)







No, it's STAINLESS.
 
Back
Top