Best sealant?

Caulks are not the best thing to use on a Vintage Trailer. They are a patch at best and will not make up for failed putty... New RV putty tape is the sealant of choice. It is applied under the flange of windows and doors, plus the J rail.

Your windows should not need sealant if they have been re-puttied. Putty will seal the screw holes and the flange; no need for sealant. If the J rail has been properly cleaned and installed with new putty, the same thing: no sealant needed.

You sound like you are wanting to do a "neat" job on the sealant which is good, but the trailer will be much neater without caulk. If you feel you have to add a sealant, try to keep it as invisible as possible. A product I use is clear OSI gutter seal, available at Lowes. It comes in a "toothpaste" type tube or a caulk tube. It takes a very small amount to seal tiny imperfections and smooths perfectly with paint thinner. I do NOT seal windows and J rail with this product, but instead use it on the skin folds, old staple holes and small cracks before installing the windows and J rail.

Please read this thread: vintagetrailertalk.freeforums.net/thread/213/question-on-caulk

Cowcharge, you are correct. I have used a thin sealant over the top putty in the past. Nowadays, I'm happier not doing so.

I don't put a sealant over putty, especially if it will "show". Sealants are only necessary when there are gaps that the putty isn't filling or if you suspect the putty might dry quickly.

My 60 year old canned hams have no sealant and some of the putty is still in good condition! Not all, for sure ) I think it matters where the trailer has "lived" whether the putty fails or not. In a very hot desert clime, I would be a lot more prone to use a thin sealant on the putty.

NOTE: Always "seat" the J rail after installing with new putty, using a rubber hammer at the top edge. Most of the time, the aluminum will mold itself to the trailer. It is easy to see "iffy" areas with gaps that might need a thin layer of sealant.

Thanks for asking. Never hurts to clarify.

Oops, sorry, I didn't see this.

I screw the J rail tight to the body with putty oozing everywhere. <GRIN> Oozing putty is a good thing...

After the putty has been trimmed (first time), I pound on the top J rail edge with a rubber hammer. The aluminum bends into the putty and body. You can see it seating and making a tight putty seal. I also use a curved piece of wood if necessary in areas that need a little more "umph". Do not re-tighten the screws, but you might need to re-trim the putty.

I learned something lately: when installing J rail on newer (60s/70s) trailers, add a thin strip of putty on the otherside. That's not the top edge, it's the under side where the lip is. The extra strip of putty helps seal against the trailer. Poking putty is never fun but that little strip helps.

Im using larger putty tape now but I like Vikx's idea about bending/beating in the j rail afterwards and will be trying that perhaps. You can get putty tape that is thicker and or wider. On J Rail, from now on I will be using one inch by 1/8 thick tape instead of the 3/4 inch stuff. A little more cost but it looks better afterwards and no sealing needed.

As far as painting is concerned, I have painted all my J Rail to this point. I usuallly use new J Rail and it gets painted along with the trailer. But I want to do one without painting the J Rail. I think the trimmed out look of unpainted J Rail will look good so I want to give it a shot on a trailer soon.

If you need a test trailer, I'll throw mine in the ring for unpainted j Rail!