Questions about Silicone caulk removal

Hey Guys,

I have begun caulk removal on my 2006 2720. I have the "opportunity" to remove what appears to be silkaflex over the original silicone. I haven't settled on a replacement product yet but I am leaning towards ProFlex RV Flexible Sealant. My concern is removal of the original silicone sealant. From what I have read nothing will stick to cured silicone sealant. What have you guys used to prep the plastic / painted metal surfaces before laying down your new sealants? The last thing I want is to spend all this time removing and applying if it's not going to stick.

Thanks!

[Wavery]

Originally Posted by greentrail

Hey Guys,

I have begun caulk removal on my 2006 2720. I have the "opportunity" to remove what appears to be silkaflex over the original silicone. I haven't settled on a replacement product yet but I am leaning towards ProFlex RV Flexible Sealant. My concern is removal of the original silicone sealant. From what I have read nothing will stick to cured silicone sealant. What have you guys used to prep the plastic / painted metal surfaces before laying down your new sealants? The last thing I want is to spend all this time removing and applying if it's not going to stick.

Thanks!

Goo-Gone, mineral spirits then acetone. Do a small area at a time so that it doesn't sit on the surface too long and start to remove the paint on the aluminum. OH YA!!!!! a tooth brush.......

goo-gone is citrus based isn't it? I've got some citrus-based cleaner that's probably similar, but, like you say, it does take off paint if you're not careful.

A heavy plastic scraper to get off most of the caulk is also helpful. Or, if you're very careful, a sharp metal scraper.

And I've given up on silicone caulk. It worked for awhile but after a lot of traveling it's seeping again. It doesn't want to stick to the plastic strips on my roof.

Before investing in something like eternabond, I'm going to try 3M Marine Adhesive/Sealant 4200 next, as recommended by others on this forum. It's an adhesive as well as sealant, and can be used under the waterline, so ...

[cochise]

Originally Posted by brulaz

goo-gone is citrus based isn't it? I've got some citrus-based cleaner that's probably similar, but, like you say, it does take off paint if you're not careful.

A heavy plastic scraper to get off most of the caulk is also helpful. Or, if you're very careful, a sharp metal scraper.

And I've given up on silicone caulk. It worked for awhile but after a lot of traveling it's seeping again. It doesn't want to stick to the plastic strips on my roof.

Before investing in something like eternabond, I'm going to try 3M Marine Adhesive/Sealant 4200 next, as recommended by others on this forum. It's an adhesive as well as sealant, and can be used under the waterline, so
...

Have you tried using a #150 piece of sandpaper on the area where the silicone is to be used? Sometimes that's all that is needed.

Thanks guys for the comments. I'm at the stage where I have scraped away the silicone with the UHMW scraper that the TM factory gave me. It works well for areas where the trim is caulked but I noticed that around things like the AC, TV antenna, vents etc that it appears that those items are bedded in the silicone. I'm wondering if anything I put down will have trouble sticking. Wondering how you guys tackled that part.

[ShrimpBurrito]

I saw this stuff at the hardware store the other day. I've never used it or heard from anyone who has, but it might be worth a shot. 3M products, while expensive, are generally top-notch.

http://www.amazon.com/3M-2153DC-NA-C.../dp/B000H5VNG8

Dave

EDIT: I just decided I'm going to try this stuff this week on some caulking around my home kitchen sink.

[Wavery]

Originally Posted by brulaz

goo-gone is citrus based isn't it? I've got some citrus-based cleaner that's probably similar, but, like you say, it does take off paint if you're not careful.

A heavy plastic scraper to get off most of the caulk is also helpful. Or, if you're very careful, a sharp metal scraper.

And I've given up on silicone caulk. It worked for awhile but after a lot of traveling it's seeping again. It doesn't want to stick to the plastic strips on my roof.

Before investing in something like eternabond, I'm going to try 3M Marine Adhesive/Sealant 4200 next, as recommended by others on this forum. It's an adhesive as well as sealant, and can be used under the waterline, so ...

3M 4200 is not as aggressive as 5200.If you are really serious about stopping a leak in a particular area, 5200 and 30 days of curing will solve the issue.

Just be aware that this stuff is semi-permanent and does NOT come off without a real struggle.

I would try a small amount of whatever you use in a small area, to be sure that it adheres to the plastic. If they are buying molding from China, chances are it may be polyethylene. If it is nothing will stick to it.

Originally Posted by harveyrv

3M 4200 is not as aggressive as 5200.If you are really serious about stopping a leak in a particular area, 5200 and 30 days of curing will solve the issue.

Just be aware that this stuff is semi-permanent and does NOT come off without a real struggle.

Heh, that's why I'll try 4200 next. Because 10:1 I'll have to strip it off and go to eternabond. Or roughening the plastic strips could help too.

By the way, Talked to Ed at trailmanor yesterday and he says they are now using 3M 760. But if that's what they originally put on my Elkmont, it's garbage. I should have asked ... I think somebody here said they have changed caulk at the factory.

[Wavery]

Originally Posted by brulaz

Heh, that's why I'll try 4200 next. Because 10:1 I'll have to strip it off and go to eternabond. Or roughening the plastic strips could help too.

By the way, Talked to Ed at trailmanor yesterday and he says they are now using 3M 760. But if that's what they originally put on my Elkmont, it's garbage. I should have asked ... I think somebody here said they have changed caulk at the factory.

Bruce,

If those moldings are made of polyethylene plastic (and I'm not saying that they are), sanding won't help.

Polyethylene plastic is like candle wax (only harder). No matter how much you sand a candle, no adhesive will stick to it.

Try putting a dab of 3M 4200 directly on top of the molding (in an inconspicuous spot). Let it cure for about a week then take 1 corner of the dab of 4200 and see if you can peel it off. If it peels off, the 4200 is not compatible. You should have to aggressively scrape it off with your fingernail or a plastic scraper.

BTW.....both 4200 and 5200 clean-up easily with mineral spirits before it cures. If you run a bead of caulk down the seam, put some mineral spirits on your finger and run it over the bead. That will smooth out the bead, force caulk into the crevice and remove unwanted residue. Don't use a lot of mineral spirits because it will degrade the adhesion. Don't use mineral spirits at all after the caulking starts to skin over. It works best if you do a 5-8' section at a time.

It's also important to wipe the area clean with acetone before caulking. I think this is a step the TM may fall short on. I'm thinking that the finish coating on the new TM skin may have some residue that might keep any caulking from adhering well.

Just saw this on a new products website, FWIW:

"The new sealant, Dow Corning 758, is a silicone caulk that the manufacturer claims will stick to polyethylene, polypropylene, vinyl, polyolefin housewrap (for example, Typar), peel-and-stick flashing (including Vycor and Tyvek window flashing), and peel-and-stick membrane (including Ice and Water Shield). The broad range of materials to which it sticks makes the caulk particularly useful for window installation.

Dow Corning 759 is said to be a low-VOC product."