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-   -   Caulking and Sealants (silicone, parbond, vulkem & more) (

Chuck 07-16-2002 02:30 PM

Caulking and Sealants (silicone, parbond, vulkem & more)
perusing through the threads, I'm wondering: should I pro-actively seal all the seams on my "new" ('73) trailer, or just large gaps or known leaks? (there aren't any that I know of...yet, except perhaps a sloppy sillicon job around the front window). I'm reading that vulkem needs to be run in a rather thick bead....I can't imagine how that would look running up and down the trailer (yuck). Or is there some method for getting it into the seams, making it more or less invisible?

What is this "par-bond" stuff, and where do I get it?

what about the alluminum gutter/flashing caulk available at HD?

airstreamcaravel 07-16-2002 05:28 PM

It "seems" to be a problem
Ditto! I have the same question. Anyone have some good proven techniques?

What is the best product?

Inland RV Center, In 07-16-2002 06:19 PM

Vulkem is used for the large seams, such as at the top of the windows, entrance door, vent cover flanges and awning rail. It's also used to seal the vent pipe gaskets, through the fiberglass screening and on to the black vent pipes.
Parbond, comes in 5 ounce tubes and is used for small seams, such as segment seams and around the top and both sides of clearance lights, and around the sides of the window frames. It, like vulkem, never completely hardens. Very small beads can easily be made with Parbond.
We have used it for many years and keep much of it in inventory.


PeterH-350LE 07-16-2002 07:03 PM

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If you want your seams and windows look like this read on.

PeterH-350LE 07-16-2002 07:07 PM

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get some 3M blue tape, 1" and 1 1/2".
On straight seams, place 2 strips leaving about 1/16" space, on corners place a piece of 1 1/2" tape and cut it with an Olfa type knife.

PeterH-350LE 07-16-2002 07:16 PM

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carefully remove the side on the skin and place it 1/16" from the frame for a perfect fit.
I personally like Tremco's (same co that makes vulkem) Dymonic Polyurethane Sealant. It sticks like thunder to aluminum and clearcoat and never dries hard. It is more liquid than vulkem and not so gritty. The color is a grey/aluminum. I bought it at the local glass company for $5.25 for a 11 oz tube. After forcing it into the seam using a caulk gun, I use a rag with paint thinner to smooth it out prior to removing the tape.

airstreamcaravel 07-16-2002 07:35 PM

I'm all caulked up! Oohh haaa yaa!

That technique rocks! The product sounds interesting, I'll give it a try.


As always, may god bless and keep you in our circle.


InsideOut 07-16-2002 07:54 PM

I'll store this thread away for later...

Thanks Andy for the clarification on the different sealers...and thanks to PeterH for the technique tip! Love it!

Shari :D

davidz71 07-16-2002 08:20 PM

I've also heard that Alcoa Gutter Seal works like the Parbond. Anyone been able to compare the difference between these two products?

Chuck 07-17-2002 11:44 AM

Thanks, guys, this is great info. But my original question: should I just go ahead and "do" all the seams in the trailer, just for good measure?

Inland RV Center, In 07-17-2002 12:16 PM

Chuck. If the seams are not leaking, don't. However, if it will make you feel better, then go for it. The vast majority of exterior seams are sealed for cosmetic purposes, the exception being the roof and awning rail.


Andy R 07-17-2002 12:17 PM

Thanking members for their posts...
Please dont forget to use the Karma button to give members who post great content more points. There is also a field for comments where you can leave more praise. This will allow the archive to stay "on topic" with less post to sift through when looking for specific content.



64GT 07-23-2002 07:23 AM

Inland Andy - 1 more time for the blond!

I saw a post of your's not long ago that said caulking the seams was useless but sold a lot of vulkem. So in the post above are you saying 'yes' to sealing the seams on the roof (but not the sides).


Inland RV Center, In 07-23-2002 08:44 AM

Seam sealing
Sealing the seams on the side of a coach, is usually cosmetic. If indeed there was a water leak on the side, it would indicated severe abuse or structural damage. Sealing the roof is another matter. Since the roofs receive far more sun exposure than the sides, a failure of a sealer can occur. It is wise to check the roof periodically for a sealed area that may have opened up.
Generally speaking, the vast "majority" of Airstream water leaks are caused by the owner. Simply not balancing the running gear properly, AND, not keeping it that way, causes at least 98 percent of all water leaks. Extremely rough roads, cause the rest. Rarely, will anyone ever find or hear of an Airstream trailer, that has been parked for years, having a rain water leak.
That in it self tells where the problem starts.
On the other hand, most water leaks, in fact, are not at any seams, but are most likely from worn out window gaskets, sewer and drain line vent pipe gaskets that are cracked ( these should be replaced every 5 years or so), leaky clearance lights (caused by simple sun exposure which shrinks the plastic), bad or missing ceiling vent cover gaskets, and of course, missing rivets.
Awning rails usually take a beating, when the awning has been used for extended periods of time. Notice how a small wind makes an awning flutter, let alone high winds. That fabric movement puts a great stain on the awning rail.
Any resealing should be carefully considered, before any application of a sealer. If there are no leaks, then leave it alone.
Like they say, "if it ain't broke, don't fix it."


stellablu 09-08-2003 11:13 AM

How to apply Vulkem?
Well, spent the weekend removing the gaskets around the doors and two little windows (same side). Now just have to get the gaskets back on.

question is - notice places that had Vulkem? and need to reseal between where the window and skin meet. I tried using a small syringe in the corners of the windows but guess I'm not doing it right.

Please someone tell me how to appy this stuff - with a syringe or your fingers??


cmgirdwood 09-08-2003 12:24 PM


Please Say You haven't used that dredded V stuff yet.
Even the factory is using the GE Alumin. Silicon caulk that you can get from Home Depot Etc.
Much easier (small caulking gun), color matches, and stays pliable forever.

InsideOut 09-08-2003 12:58 PM


Even the factory is using the GE Alumin. Silicon caulk
...maybe so with the newer trailers, however, Vulkem was the sealer used in the vintage trailers. From our experience, the two do not mix well. We had a PO that used silicone caulk over the old Vulkem and we had nothing but problems with it adhering. I believe it is better to stick with the original, rather than mixing the two, to save yourself a bunch of future problems.

We applied the Vulkem using a syringe and masking tape. There was a great thread posted a while back that's packed with info & "How To's" to help you out, here's a link:

Tell me more about caulking...

Shari :)

j54mark 09-08-2003 04:37 PM

All the Vulkem I ever have used came in a tube for a caulking gun. Is it available in some other form?

I have seen nothing about AS switching to aluminum silicone caulk. I understand they switched to Sikaflex some time back; I have used some and it seems to be an excellent product as well. The color blends a bit better with the aluminum than Vulkem.

Vulkem appears to remain pliable for decades. Maybe longer.

For really small seams I like Parbond.


thenewkid64 09-08-2003 05:01 PM


The Vulcem is only sold in gun tube cartridges for the general public to buy.

Some members transfer some to a large volume syringe to have better control over the bead size when sealing smaller seams. I can understand this as the par bond seems to develop a hard cracked finish look as it ages. The Vulcem stays soft and finished the way it was when you left it.

Chas 09-08-2003 05:41 PM


Originally posted by mareinmn

Even the factory is using the GE Alumin. Silicon caulk that you can get from Home Depot Etc.


Really? What factory, maybe you can cue us in on where you got this bit of info.

Myself, I seriously doubt it. I remember a pic posted here somewhere that showed a case of Vulkem right on the production line. Yes, Vulkem can be messy but will hold up decades longer than any silicone, don't care what the tube says, 25 years, thirty years, all baloney!! I've peeled into some of the thirty year old Vulkem on mine and it is almost as fresh as the new stuff out of the tube, and stays stuck like nails.


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