C-10 Flow Seal - Anyone Used It?

[Frank&Mike]

I went to the local Airstream Dealership to purchase Vulkem. The guy in the Parts Department said they don't sell Vulkem. All I have ever known to use on an Airstream was Vulkem. He asked what I was going to use it for and I replied that I need to seal a couple of leaks (one on the Skylight and another above the Rear Bedroom Window). He said Airstream uses this stuff called C-10 Flow Seal Self Leveling Caulk Sealant (photo attached).

There are very few directions on the tube.

1. Does anyone have any experience using this stuff and can offer any suggestions on their experience in using it?

2. Do I tape off the area to get clean lines like you do with Vulkem and other sealants?

3. When I was on the ladder this weekend (washing and waxing the Airstream) I could see where there appears to be this white sealant on many components on the top of the Airstream. Are all of these little "ice cream looking" places where Airstream used this sealant?

Hope I purchased the right stuff at $14 a tube.

[Lance M]

Hi Mike,
1. They do sell Sikaflex 221 in gray at CCII. That is what AS uses in the manufacturing process nowadays. It is similar to the old Vulkem formulation. Your roof is white, so the C-10 will blend in well. I have used C10 before. I used it on the flat seams around the TV antenna mounting points, the seams of the Armstrong A/C mount rivets, and the vents. It is self leveling, so it will smooth out to a nice smooth surface.

2. No need to tape it off on the roof seams. I don't think it should be used for any vertical seams like exterior window seams.

3. I think AS uses Dicor lap sealant or some other brand of self leveling sealant.
I would use TremPro 635 on the window seams.
You can get TremPro 635 (the new Vulkem) from Fastenal or VTS, ODMRV et al..it also comes in white if you'd prefer TremPro for the roof seams.
Oh btw, Crestview in Georgetown has C10 as well for cheaper IIRC

[Frank&Mike]

Hey Lance. Thanks very much for the reply and information. It's much appreciated. I still need to get on your calendar (to get some service on the Airstream) after the first of the year when our calendars work out. Have a great Holiday!

[lewster]

C-10 has a slightly thinner consistency than Dicor Self-levelling Sealant. Both work well, but I think the C-10 should be around $10/tube.

The Airstream factory uses SikaFlex 221 in grey on the seams of newer Airstreams. I use cases of all 3 with great success. I don't use Vulkem as it has a grainy consistency, unlike SikaFkex, which is butter smooth. VMMV!

[Frank's Trailer Works]

only use that FlowSeal on things like flat seams and skylight curbs. It flows like you would not believe. It is not like Vulkem in any way. It is more like spreading honey.

Lance and Lewster are two top notch guys and give very solid advice. I must however clarify something they both said;
Vulkem is now made by Trempro. It is called Trempro 626. The real original formula is NOT 636, 635, 689, or any of the other products made by Trempro. The original Vulkem is #626. It is a textured polyurethane sealant. SikaFlex does not make Vulkem, they make their products. I think when you visit the factory you will see them using what ever product they got a good purchase on and not so much a loyalty to any one maker of "Vulkem" as everyone likes to call any sealant on an Airstream.