Sealing Drip Rail

Ready for something new? Try the Palmer Boys Method for sealing your skin edges.

I teach this method (using a body skin model) in my VCT Boot Camp Class each March. With this method, you do not need drip rails or putty to seal the edges. The rails, and the putty then become cosmetic.

This method is used when you have a "fold over" roof edge. You take a piece of 3/4" (19mm) masking tape and carefully cover the edge leaving approximately 1/8" of roof skin showing at the edge. You want to place this tape as smoothly and symmetrically straight as possible to give you a nice smooth curved edge. DO NOT BUY YOUR BLUE 3M MASKING TAPE AT A HARDWARE STORE, OR A BIG BOX STORE. Buy your 3M green tape from a auto body paint supply store. Trust me on this advice. The blue tape does not stick, the tape from the auto body supply sticks. Do not leave any masking tape on the surface for more than a few days, and never in sun light. Use a roll of 1/2" green 3M tape and smoothly place it on both sides of the 3/4" masking tape you already placed. You should now have three pieces of masking tape on the wall edge of your trailer. The next step is to remove the 3/4" tape from the middle, and this will leave a nice 3/4" wide area with the roof skin edge and all of your crown staples. If you took your time laying this out is will look nice. Make sure you run your finger over the edge and staples and hammer down any high spots.

The next step will be to use a "paintable" urethane seam sealer over this 3/4" bare metal area. I use grey TremPro 635 which is only about $7 per tube. Cut the caulking tube to a 1/8" bead, apply a small amount and spread it out, working it into all of the sharp edge, and staples. A disposable acid brush works best. A little goes a long way. It's easier to add more, than it is to figure out what to do if you apply too much. Work only about a 12" to 18" section at a time because it will start to skim over. It will self level, you will not see the brush marks after a day or two. This product is heat sensitive, I store my unused tubes in my shop refrigerator. Do not freeze it just keep it cold and it will not harden up on you. This is a urethane product, it is NOT a silicone, you can paint your graphics right over it after it fully dries. Depending on ambient temperature and humidity, it will take a few days to a week to dry. You want to pull the 1/2" guide tapes off when the sealer becomes sorta dry to the touch, but before it's fully dry. Again if you took your time placing your first guide tape you will end up with a very nice 3/4" sealed seam covering you roof skin edge. This becomes a very strong bonded seam after it cures for a few weeks out in the sun.

Apply your putty and edge trims "after" you paint your graphics. If you have some "booger areas", it usually best to let them dry then clean them up. You can rub and roll the product up before it's fully hardened. If you working with bare metal (not painted) Acetone cleans it up. If your working with pre-painted skins try some denatured alcohol for clean up. If you try to clean the product when it's wet, it's a mess.

VTS is out of this product "much of the time", so order it early, and store it in a cool place or it will not last. I sometimes have to order it in white, it works the same as grey and you can mix the colors because your going to cover it, paint over it anyway in most cases.

This is not internet dreaming, I have used this method for the past five years on my trailer reskins with great success. This is a seam sealer just like you would use to seal welded body panels on a car.

I also do a double wrap on my wall and roof skins that we can discuss another time if you have any interest.

John

Rod, The rule is to never leave masking tape on any metal surface for any more time than necessary.  The adhesive dries and the paper tape becomes harder to remove the longer you leave it on the surface.  It does not matter why we are using masking tape, for paint, or for urethane sealer. just keep it cool and out of the sun/high surface temperature, and remove it asap. 

TremPro 635 quickly begins to skim over at normal outside temperatures (the volatile solvents evaporate).  You want it to be liquid so it can be easily spread with the brush.  If it's still liquid and not drying it will self level which gives you a nicer finished surface.  i rotate the trailer side 180 degrees.  Apply it on the cool shady side, then flip the trailer around and bake it on the sunny side.  Kind of low tech, but it works.

I would never recommend that you use the urethane sealer on the flanges for a vent.  After it fully cures in a couple of weeks, you will need to use dynamite to remove the vent if service is ever necessary.  It might work OK for the dab required on the screw heads, but not on the flange.  Just use the normal 1/8" by 1" wide RV putty, like has been done for the past 70 years.

One other thing, The TremPro 635 seems to hold up well to the sun UV rays.  I test it by leaving my Spartan outside 365 days each year for the past five years.


John 

First, I have tried all of this stuff, LOL.  Some of it works, some not so great.  If I take the time to pass it on, trust me, "it works".

I have tried to place RV putty, or Urethane sealer under the fold over and "wait for the drum roll"......it does not work.  What you end up with is an uneven roll over edge.  The putty/urethane prevents the metal from laying down.  If you try it you will have countersunk puckers at each staple/screw, it does not look nice.

Because I use a "double roll over" when mounting skin, I like to keep the edge corner nice and square.  On some of the old 1940's and early 1950's riveted skin trailers they used a black cloth tape on the seams and placed it between the two pieces of aluminum at the lap joints.  Then the rivets went through the tape.  It's hard to say what the black goo adhesive was on the tape because after 70 years it's all dried out.  If your old enough to remember black "friction tape" that is what the old sealing tape looked like.  Friction tape was "old school" black electrical tape.

The "Double Roll Over" method we are talking about is when you first roll over the wall edges, then staple from the top as step number one.  In step number two, you fold over the roof skin, then staple from the side.  Step number three is when you come along with the urethane and seal all of the roof metal edge, and seal all of the staples on the side.  When done, you would not be able to even tell it was done differently.  It's a double edge, over lapping seal, that has a urethane sealing the raw edge.  Frankly you could leave the awning and drip rails completely off and it would still be water sealed. 

John

No apology needed. Love all the ideas. Wish I had been privy to it earlier, lol.