Sealants Summary ...

[Ahroc]

Hi silver twinkee (with good stuff inside) comrades
It seems there are gray color choices, and because I want to start out this process on the right foot...
Should I purchase Sikaflex 221 gray? or aluminum gray?
Thanks

[wcronin4]

Kudos to TinTin for envisioning this thread and for the significant contributions from "lewster," for sharing his significant experience.

My 78 Sovereign has many leak issues I working through, but my question relates to the proper way to install and apply sealant to an aluminum patch. I have two patches to install, one on the roof to cover the hole left from on old corroded TV antenna, and I want to eliminate the internal battery compartment and replace the old door with a patch.

One application is on the roof. One application is on the front (side). How should the sealants be applied (probably will use Sika products) both on the inside and the outside of the patch?

What would be most helpful to me is understanding the process once the patch is made and ready to install? For example, do you put sealant between the patch and the skin? In the case of the roof, so you use a self leveling caulk on all the rivets and around the edges of the patch? How do you seal up the interior side of the patch, or is that necessary?

Would really appreciate your input.

[perryg114]

Recent observations using Trempro 635 and Parbond. The Trempro shrinks and cracks over time and it tends to have poor adhesive strength and not great tensile strength. It does ok where you have a really thick fillet joint 1/4" or bigger or a flange where it is applied between the two flanges. It does not like movement like on an awning bracket and it does not do well with narrow cracks. The Parbond seems to have better properties and it is a much stronger adhesive. It gets a crust on it eventually and falls apart but up to that point it performs well. The Parbond has better elongation so it does not crack as bad in shifting areas. Probably best to use several layers of this stuff since the top layer can get crusty after several years. These are observations in the 5-10 yr range. I bought my trailer in 2011 and have done a lot of work on it over the years. So consider this a long term test. I will post some before and after photos around some windows where I used Trempro as soon as I get a chance.



Perry

[Ultraclassic]

Originally Posted by TinTin

I've been reviewing the forums to determine which sealants to buy for water-sealing maintenance on my new-to-me Airstream. I've come up with the following list of sealants from the posts of others. If anyone has suggestions regarding these sealants, suggestions for better products, or sources for these products, I'd really like to hear them!!

For wheel wells/underbody:

Vulkem 116
Trempro 635

Roof

Silkaflex 721 White

Windows/Trim

Silkaflex 221 Gray
Parbond Gray or Clear

Small seams (between aluminum panels)

Acryl-R

Hi Gang is this list still good to use

[wcronin4]

Yes, although I find parking to be difficult to work with because it can’t be “tooled” after it has been applied. Sikaflex is better

[gator.bigfoot]

Originally Posted by Ultraclassic

Hi Gang is this list still good to use

I prefer the dymonic 100 over the Vulcem 116.

Much easier to tool.

[DanHogHunter]

Originally Posted by Ultraclassic

Hi Gang is this list still good to use

I'm having to replace a skylight. Do the caulks mentioned for Windows/Trim apply to the skylight?

[wcronin4]

If it’s mounted to the roof, you should be using a self leveling caulk like Dicor or Sikaflex

[DanHogHunter]

Thanks, when you say Sikaflex I assume you are referring to 221. As near as I can tell 721 doesn't seem to exist anymore.


Best regards,
Dan

[wcronin4]

Dan - I was referring to 721. 221 is not self leveling.

I had to patch some holes in the roof of my Sovereign where I removed one of my ceiling vents. Between the patch and the roof I used 221 and when all the bucked rivets were installed I cleaned up around the edges with mineral spirits. Then I went over the edges of the patch with Dicor self-leveling caulk. I also used Dicor around a new MaxxAir vent and new TV antenna.

Hope this helps

[ROBERT CROSS]

I have used 3M 4200 and covered with Extreme Sealing tape, 8 years plus...SFSG 👍

Bob
🇺🇸

[Ultraclassic]

Originally Posted by ROBERT CROSS

I have used 3M 4200 and covered with Extreme Sealing tape, 8 years plus...SFSG [emoji106]

Bob
[emoji631]

Hi Bob

In your picture of the roof vent it appears to be just the tape? Or did you use the sealant under the flange and then tape on top....

I think I answered my own question.

That tape is expensive (shipped to the great white North)

[FloydCoVa]

Originally Posted by ROBERT CROSS

I have used 3M 4200 and covered with Extreme Sealing tape, 8 years plus...SFSG 👍

Bob
🇺🇸

Hey Bob, I followed one of your earlier postS and you didn’t mention the 3M 4200. I cleaned mine with braklean then just used the tape. Should I redo or just leave it be with just the tape.

[ROBERT CROSS]

Originally Posted by FloydCoVa

Hey Bob, I followed one of your earlier postS and you didn’t mention the 3M 4200. I cleaned mine with braklean then just used the tape. Should I redo or just leave it be with just the tape.

Just leave it...if the original is not compromised the tape will protect it very well.

That is what I did with my original skylight, 'til it cracked and had to be replaced anyway.

Bob
🇺🇸

[chaseav]

Originally Posted by FloydCoVa

Hey Bob, I followed one of your earlier postS and you didn’t mention the 3M 4200. I cleaned mine with braklean then just used the tape. Should I redo or just leave it be with just the tape.

AGREED! You snuck that 3M 4200 caveat in here much later, Bob. I'm getting a water leak by the door; happened once before and incorrectly assumed it was condensation from the over zealous ducted AC vent + door my wife and kid can never seem to fully close. It's apparent though now in major rainfall, it's NOT condensation. I'm thinking it's coming from the less than fantastic, Fantastic Roof Vent. Minor cracking at the flange, but caulking is falling apart... may just clean and use "Bob's crazy tape" for a fix.

[DanHogHunter]

Originally Posted by ROBERT CROSS

I have used 3M 4200 and covered with Extreme Sealing tape, 8 years plus...SFSG 👍

Bob
🇺🇸

Hi Bob, did you purchase this from Amazon? Reviews there are indicating some problems with delivery of the desired product. The 3M 4200 is showing up without the nozzle, damaged, or partially cured.

The Extreme Sealing tape is being called out as fake, not the actual 3M product. The tape is not one continuous length and the cardboard core doesn't have the 3M brand on it.

[lsbrodsky]

I get my supplies like this from McMaster.com. But, there are many sellers of 3M tape that repackage the tape in smaller rolls so that you will not see 3M on the cardboard. I really do not know how to verify whether it is 3M or not, but I know the stuff I buy from McMaster always works like it supposed to.
Larry

[DanHogHunter]

Has anyone done any research comparing Clear Gorilla Tape to the 3M 4412N tape? The reviews for Gorilla tape are very good and the cost savings would be substantial.

[nvestysly]

Originally Posted by DanHogHunter

Has anyone done any research comparing Clear Gorilla Tape to the 3M 4412N tape? The reviews for Gorilla tape are very good and the cost savings would be substantial.

A quick review of the Gorilla and 3M web sites shows some substantial differences/unknowns:

Thickness:
Gorilla - unknown
3M - 0.080 inch

Release Liner:
Gorilla - No
3M - Yes

Service Temperature:
Gorilla - 140F
3M - 200F

And I'll add the following anecdotal/editorial...

Seat of the Pants Factor:
Gorilla: very good, better than most
3M - world class industrial adhesive manufacturer

The Gorilla product looks interesting and I may put some in my toolbox for various uses. After doing some research on the 3M product a few days ago I think I'm adding it to my toolbox for long-term sealing jobs that I don't want to do again for several years.

[DanHogHunter]

Originally Posted by nvestysly

A quick review of the Gorilla and 3M web sites shows some substantial differences/unknowns:

Thickness:
Gorilla - unknown
3M - 0.080 inch

Release Liner:
Gorilla - No
3M - Yes

Service Temperature:
Gorilla - 140F
3M - 200F

And I'll add the following anecdotal/editorial...

Seat of the Pants Factor:
Gorilla: very good, better than most
3M - world class industrial adhesive manufacturer

The Gorilla product looks interesting and I may put some in my toolbox for various uses. After doing some research on the 3M product a few days ago I think I'm adding it to my toolbox for long-term sealing jobs that I don't want to do again for several years.

Thanks for your reply. On the Amazon product page I found that the thickness is .18 mm or .007 inches which is very significant, if it's correct.