Posted 2005-03-31 6:50 PM (#23269) Subject: What's the best caulking to use on steel?
Veteran
Posts: 140 Location: Colorado
Any advice on what type of caulking to use on the interior of my trailer, where I am going over painted steel (caulking the joints between beams and sheet metal)? Will plain old DAP Silicone I work well or do I need something specifically for trailers? I expect it needs to handle temperature differentials and road vibration.
Posted 2005-03-31 10:20 PM (#23280 - in reply to #23269) Subject: RE: What's the best caulking to use on steel?
Expert
Posts: 2689
I don't think I'd even bother to go to silicon, just use DAP acrylic caulk.
I don't think you need to waste the extra money.
Or, WHY use silicon ?
You're probably going to paint over it anyway, there is little chance of it drying out and cracking.
Posted 2005-03-31 11:29 PM (#23282 - in reply to #23269) Subject: RE: What's the best caulking to use on steel?
Member
Posts: 39 Location: Covington, Louisiana
I've just gone through the same process on my horse trailer and these are some of the things I've found. I would not use silicone if you are planning to paint the area because it will not take paint. There are some brands that are advertised as paintable but even those don't take paint well. Also I don't think the acrylic caulks are a good choice because they don't stand up to vibration too well but they are cheap. Probably the best choice is a polyurethane caulk sold for flashing and metal windows. It is a little more expensive than silicone, sticks to clean or clean painted metal well, remains flexible and will handle vibration and is paintable. You should let it dry for about a week before painting it but I painted some of mine in about 4 days without problems. I got it at Home Despot but you can find it at most building supply stores and hardeware stores. There are some made for use on trailers & RVs that you can find at RV stores.
At the top of the heap there are several specialty caulks/seam sealants made for use on automobiles that will do a good job on your trailer. They can be found at auto body supply shops but they are pricey and a lot of them require special applicators. Hope this is some help.
Posted 2005-04-01 9:46 AM (#23286 - in reply to #23269) Subject: RE: What's the best caulking to use on steel?
Veteran
Posts: 140 Location: Colorado
Thanks... The caulking is going on seams that will be covered by panelling and insulation so it will not be painted over. Silicone was recommended on an RV site, so that's why it was my first thought. I'm not too worried about it costing a little extra for better caulking, if the more expensive product actually works better.
Posted 2005-04-01 1:38 PM (#23306 - in reply to #23269) Subject: RE: What's the best caulking to use on steel?
Veteran
Posts: 233 Location: Tennessee
I'm wondering why you would caulk the interior instead of the exterior. I am about to order some "Proflex" RV roof sealant for my trailer that has been caulked to within and inch of it's life but is STILL leaking. My interior is already finished so I have to go outside. Has anyone used this product?
Posted 2005-04-01 1:51 PM (#23309 - in reply to #23306) Subject: RE: What's the best caulking to use on steel?
Expert
Posts: 2953 Location: North Carolina
Originally written by Sheryl on 2005-04-01 2:38 AM
I'm wondering why you would caulk the interior instead of the exterior. I am about to order some "Proflex" RV roof sealant for my trailer that has been caulked to within and inch of it's life but is STILL leaking. My interior is already finished so I have to go outside. Has anyone used this product?
Sheryl ... I've felt your pain ... If it's still leaking, you haven't caulked the right place. Try to remember that point as your caulking. Sundowner uses this caulking on the exterior of their trailers. It's very durable.
The caulk used is a moisture cured polyurethane. Manufactured by Sika Corp.
30800 Stephenson highway
Madison Heights, MI 48071, 248-577-0020
The name is Sikaflex - 221 SF, Product code is 220-242
The color you want is "AL Gray"
You might try marine / boat supply as a place to purchase it too.
Posted 2005-04-01 2:53 PM (#23311 - in reply to #23306) Subject: RE: What's the best caulking to use on steel?
Veteran
Posts: 140 Location: Colorado
Oh yes, the outside is going to be fully re-painted, re-caulked, and I'd like to do a rubber rooftop coating eventually.
However, I am working on the interior at this point, and the way it was originally done was caulking in all the joints (which was removed prior to sandblasting the interior). I think the reasoning for caulking inside is to prevent condensation from getting between the beams and sheeting (?).
I am going to re-caulk the roof before it's repainted, though, as a temporary measure to prevent leaks this summer. I scraped most of the old caulking off above the LQ today, and plan to caulk it back up this afternoon. I will remove that caulking when the repainting is done in August. I got some of the 'door and window flashing' caulk for that.
There is a seam between the fiberglass nose and metal that was really crappy looking, so I'm glad I climbed up there and am getting that caulked up better.
Posted 2005-04-01 4:46 PM (#23317 - in reply to #23311) Subject: RE: What's the best caulking to use on steel?
Expert
Posts: 2828 Location: Southern New Mexico
That fiberglass nose is what's killing me. It just WON'T seal. The local welder told me of a trailer place not to far from here that sells the metal noses. I may go get one and have him weld it on and forget the calk!
Posted 2005-04-01 4:48 PM (#23318 - in reply to #23317) Subject: RE: What's the best caulking to use on steel?
Veteran
Posts: 140 Location: Colorado
Hi Terri, thanks for posting about this. That would be a good option for me if I run into trouble with the trailer nose. I hadn't thought of replacing it with a steel nose.
Posted 2005-04-01 4:57 PM (#23320 - in reply to #23269) Subject: RE: What's the best caulking to use on steel?
Veteran
Posts: 140 Location: Colorado
Ok, I taped the seams off (glad I did) to keep caulking in boundaries. I was using a self levelling caulk... Ran a bead, then used a gloved finger to push caulk into groove and within taped boundary. Then pulled up tape before the caulk permanently attached itself to it. It came out looking reasonably nice for a first try, but it was still a sticky mess. Guess I might run a second bead directly over the seam after this sets up a bit. Then the true test comes - the garden hose.
Will it leak? Most likely, but being a pro at removing caulk means I can try again.
Posted 2005-04-02 10:48 AM (#23341 - in reply to #23318) Subject: RE: What's the best caulking to use on steel?
Expert
Posts: 2828 Location: Southern New Mexico
I figured that just replacing the fiberglass would work best. I am already going to have all the calk removed and the seams welded when (if ever) I have the trailer repainted. I was hoping for a really bad hail storm so I could get a whole new roof coutesy of the ins. company. But that would mean lots of other stuff damaged, so I guess I'll just have to pay for it.
What's the best caulking to use on steel?
I am about to order some "Proflex" RV roof sealant for my trailer that has been caulked to within and inch of it's life but is STILL leaking.
My interior is already finished so I have to go outside. Has anyone used this product?.jpg)
