Sealants Summary ...

[Jeremy9107]

Great thread. I found Lewster to be a reliable source for these sealing inquiries. To reiterate his advice to me...
--Acryl-R (can with applicator, not caulk tube) for all side panel seams, rivets and rub rails.
--Sikaflex 221 for basically everything else. So I will be using it around windows, exterior lights, window glass to the frame, wheel wells, over any flanges, panel seams and rivets from inside.
--He also mentioned in this thread using Sikaflex 715 along the roof.

If sealing everything, he says (6) 10 ounce tubes of Sikaflex 221 and 1 large can of Acryl-R should be enough.

I priced out today and found Amazon to be cheapest for the Sikaflex products at around $9 per tube. (Home Depot sells a Sika product for cheaper but Lewster says this is not the right product!) Out of Doors Mart was the only place I could find the can of Acryl-R with applicator (each $34.95).

[weather command]

I may have missed the post but what experiences has anyone had with Armor Roof Seal? I think that is one of the permanent roof companies with lifetime warranties??? THANKS in advance!

[MontyV]

so this thread was talking about sikaflex 721, now i see reference to 221. but they are different aren't they? is 221 suitable?

[nvestysly]

I've used 221. I am not familiar with 721.

I usually buy Sikaflex 221 in aluminum/gray color but I've also used white depending on the application. The Sika web site indicates 221 is a non-sag, polyurethane sealant/adhesive. Non-sag means it requires "tooling" to put it where you want it at the thickness you want it. Many RV sealants are self-leveling but Sika 221 is definitely thick and needs to be shaped during and after application. I use a terrycloth rag soaked in mineral spirits to shape the mound of Sika 221 to the desired thickness.

My experience is limited and I may be applying 221 incorrectly but it seems to work. I've seen the Airstream factory repair shop using 221 and they also use a rag soaked in mineral spirits to shape the material to its final thickness.

The last time I purchased 221 I bought it from a local (non-Airstream) RV dealer. I've also purchased it from a local building supply company. Home Depot and Lowe's do not carry 221 in my area so I found a specialty, pseudo-wholesale building supply company - they are clearly the least expensive for me at around $7.50 per tube but they have limited hours compared to the RV dealer who sells their 221 for about $12 per tube.

[TheGreatleys]

Sikaflex 221 is my sealant of choice for most things. $10 a tube on Amazon.

[Robert12]

Originally Posted by TinTin

I'm adding to the above list of sealants, based on the thread by sailorii which mentioned that Airstream now recommends AdSeal products.

For wheel wells/underbody:

Vulkem 116
Trempro 635
Adseal Premium Quality Sealant Gray (neutral silicone based)

Roof

Silkaflex 721 White
Adseal Premium Quality Sealant White (neutral silicone based)

Windows/Trim/Rubrail

Silkaflex 221 Gray
Parbond Gray or Clear (small hand tubes)

Small seams (between aluminum panels)

Acryl-R (small cans)

Sir
I like the list of sealants. Having tried many ways to seal an open caulk tube
Which do not work for a long period of time, have you found a effective
Method or device that will seal a open caulk tube for a lone period of time?
Thanks
Robert

[CruizinDux]

Originally Posted by Robert12

Sir
I like the list of sealants. Having tried many ways to seal an open caulk tube
Which do not work for a long period of time, have you found a effective
Method or device that will seal a open caulk tube for a lone period of time?
Thanks
Robert

This from an old neighbor ...

https://www.youtube.com/watch?v=hHos0xpHbSE

Not really a reseal but possibly a re-use method....plus some other suggestions in the comments section


bob

[sandlapper]

Great! Thanks for sharing. John

[Airwalla]

Has anyone used the “As seen on Sharktank” Flexseal product? One can buy it from HD or Lowe’s..

[TheGreatleys]

Originally Posted by Airwalla

Has anyone used the “As seen on Sharktank” Flexseal product? One can buy it from HD or Lowe’s..

Yeah. Saw it on TV. They paint a screen door with it in a commercial and use it for a canoe bottom. I see someone at least once a month saying they're going to use it to coat the inside of the Airstream skin with it so it'll never leak again. Famous last words.

A sealant is only as good as its bond with the substrate and ... well ... there are much better products available.

[jenhansen]

My dad is a veteran yachtsman and swears by Captain Tolley's for all sealing on his boat.

We have to seal the wing windows (original seal is brittle and coming out) and I am researching what to use to repair it. According to this thread, the answer is the Sikaflex 221.

Why wouldn't Captain Tolley's be a good option for the windows?

Thanks in advance.

[TheGreatleys]

Originally Posted by jenhansen

My dad is a veteran yachtsman and swears by Captain Tolley's for all sealing on his boat.

We have to seal the wing windows (original seal is brittle and coming out) and I am researching what to use to repair it. According to this thread, the answer is the Sikaflex 221.

Why wouldn't Captain Tolley's be a good option for the windows?

Thanks in advance.

Captain Tolley's is super thin in consistency. It's great for wicking into little cracks and holes, or around leaky rivets, but it won't make a bead, so it's not good for resealing windows. SikaFlex 221 is fantastic for making a bead around windows, doors, and vents.

[TYSON PECK]

What adhesive should I use to glue the decorative vinyl strip back on the bumper guard rail that I removed checking for leaks?
2006 Bambi 16"

[ktmkirby]

What is the sealant used to seal the fridge compartment? It has more of a putty feel to it. I also found it where the gas lines go through the floor.

[TheGreatleys]

Originally Posted by ktmkirby

What is the sealant used to seal the fridge compartment? It has more of a putty feel to it. I also found it where the gas lines go through the floor.

Butyl tape? https://www.vintagetrailersupply.com...-p/vts-419.htm

[trumpetguy]

Originally Posted by TYSON PECK

What adhesive should I use to glue the decorative vinyl strip back on the bumper guard rail that I removed checking for leaks?

2006 Bambi 16"

I used 3m spray adhesive. #45

[ktmkirby]

Originally Posted by TheGreatleys

Butyl tape? https://www.vintagetrailersupply.com...-p/vts-419.htm

Not Butyl tape, but it has that consistency. Maybe Butyl caulking.

[my3sonsdad]

I am adding a window where one didn’t previously exist. The donor window frame I removed looked like it had butyl tape between the exterior skin and the window frame, so I planned to use $14 RV buytl tape from amazon along with sikaflex 221. Any alternative recommendations?

[bigcountry]

Amazon offers two different labeled cartridges for the 721:
Sikaflex 221
-and-
Sikaflex 221 "Technique"


What is the difference between the two products?
Is one preferred over the other?


Thanks!

[GMFL]

Originally Posted by bigcountry

Amazon offers two different labeled cartridges for the 721:
Sikaflex 221
-and-
Sikaflex 221 "Technique"


What is the difference between the two products?
Is one preferred over the other?


Thanks!

I have used both and can’t tell a difference. The Sika-flex website does not list the “technique” as a type like they do “LOT” or “LONG OPEN TIME”
I think it’s just a branding term.