Sikaflex 505UV in gray - where to get it?

[Alphonse]

As many of you know, the factory did use Sikaflex 721UV for the external sealant for the larger gaps, for example around the hot water heater access door. Sika stopped making 721 in gray and, as indicated here on the board in another post, 505 UV would be the recommended alternative by Sika.

Here is the issue, I can't find Sikaflex 505UV in gray anywhere in small quantities. The boat repair/hardware suppliers sell it in white but I want it in gray.

When 721UV was taken off the shelves, the AS factory changed to another product called Adseal and you can order that from the factory store. I tried to do a little research on the Adseal specs and availability and couldn't find enough information on it to satisfy me. It may be really good stuff but I have not been able to convince myself of that by searching the web.

So with this background, my two questions:
1. Has anyone found a supplier selling the Sikaflex 505UV in gray in quantities less than a box?
2. Has anyone found a good alternative to the Sikaflex 721UV or 505UV in the 3M line that may be more readily available?

Thanks for your help

[Pepthedog]

I was researching this recently myself and TremPro 635 is the new Vulkem since the original Vulkem is not being made anymore. Vintage Trailer Supply has the Trempro 635 in small quantities. It' gray. Sikaflex 505 is white and in my case (2008 Safari with a whiite roof) was the appropriate sealant. I picked some up from the dealer since he is close but it's fairly well available. Hope this helps. There are a few threads on the subject from those far more familiar than I. Search Trempro and you should be enlightened.

[Alphonse]

Originally Posted by Pepthedog

Sikaflex 505 is white and in my case (2008 Safari with a whiite roof) was the appropriate sealant. I picked some up from the dealer since he is close but it's fairly well available.

Pep, thanks for the insights on Vulkem.

Sikaflex 505 is actually made as a gray as well. The issue I have had is finding it available less than a box of 24 cartridges!

Al

[lewster]

SikaFlex 221 comes in grey (also black, white and colonial white) and is readily available in individual tubes. I have been using this for 7 years without a failure or cracking. You might consider this as well.

[Alphonse]

Thanks Lewster for sharing your experience with 221. That could be an acceptable solution but I would be cautious about putting it on top of 721 and will explain that a little more here.

In the way of a little more background I was told by a knowledgeable person that the Sika factory had told them 221 actually had some UV stabilizer in it. However I am assuming it does not have as much as the previous 721 formulation and the current 505 that carry the designation "UV". Earlier in my career, I managed a manufacturing site that made light stabilizers and antioxidant compounds. These specialty chemicals are quite complex and expensive to manufacture. Although the application dosing is typically low, it still adds significant expense to a final product to have them in the formulation in significant concentration.

I have tried to contact Sika without success to speak with them directly simply because I grew more curious about all this in my quest to find a replacement for 721. I also wanted to be sure to put the proper stuff on my AS considering that I likely couldn’t get all the 721 removed.

From the Sika specs:

1. 221 is a polyurethane
2. 721 UV was a silane terminated polymer. The 721 specs have a somewhat cryptic warning to not apply over curing urethanes. This seems to have to do with proper curing.
3. 505 UV is silane terminated polymer. Same warning on application in presence of curing urethanes.

My takeaways without the benefit of talking directly to Sika:

I. I am cautious about applying 221 on top of 721. While the 221 might be good, it quite likely doesn’t have the UV light stabilizer content that 721 had.
II. The 505 appears to be compatible with the 721 (same base material) and it has the UV designation.
III. 505 has a service temperature of up to 400F for short duration.

Therefore my quest to find Sikaflex 505 UV in gray!

[Shacksman]

Silkaflex in grey is available at Loews in the rain gutter section. I don't know what number as I am out of it right now, but it works very good on aluminum.

[cameront120]

If you have a glazing supply company near you, check with them. All of these sealants are also used in the installation of windows and curtain wall systems. I get all my Sikaflex from one such supplier.

[colberjs]

This is interesting. Sikaflex is available locally as concrete joint sealant. I will have to look at the numbers but I know it is available in gray. I'm assuming it is a different product.

[tinman1]

Alphonse,
You might try the following company - I was looking for Sikaflex 505UV (white) (not sure if have gray)for installation of my Maxim skylights - someone gave me the following company name. I purchased a couple of tubes ($5.69/tube[+ tax] - shipping $22.44 - total $34.61). Said shipping fee was high because "hazmat" applied. Go figure!!!!

Aim Supply Company
Larga, FL
Phone 800-288-3091 (ext 2504 "John")

Good luck!

[CA_Tallguy]

Just a note - I am seeing sikaflex at Home Depot near me but it just says sikaflex SL self leveling. It appears to be a formulation for concrete, which is confirmed at sikaflex website. Does not seem like a good choice for our trailers unless someone knows more about it and can say...

At lowes website, nothing is coming up for sikaflex but I would suspect that the formulation they might have or have had near rain gutters was probably more appropriate for airstreams. Still, not sure if I would use it except in a pinch without knowing if it would hold up,as well as the numbered versions that are recommended.

Well.. I am assuming that what you guys were finding at local places was not one of the specific sikaflex numbers like 221 or 721? (Yes I realize this is an old thread but I thought it might be useful to others to post this info here.)

[Gkiesel]

I know this is a very old thread but I just ordered an ac unit from PPL Motorhomes in Texas. They sell Sikaflex 505Uv in grey by the tube in case anyone is still looking.

[lewster]

Originally Posted by CA_Tallguy

Just a note - I am seeing sikaflex at Home Depot near me but it just says sikaflex SL self leveling. It appears to be a formulation for concrete, which is confirmed at sikaflex website. Does not seem like a good choice for our trailers unless someone knows more about it and can say...

At lowes website, nothing is coming up for sikaflex but I would suspect that the formulation they might have or have had near rain gutters was probably more appropriate for airstreams. Still, not sure if I would use it except in a pinch without knowing if it would hold up,as well as the numbered versions that are recommended.

Well.. I am assuming that what you guys were finding at local places was not one of the specific sikaflex numbers like 221 or 721? (Yes I realize this is an old thread but I thought it might be useful to others to post this info here.)

Their concrete formulation is different from their 221 formula, as 221 is not self-leveling and is a single part moisture cure polyurethane. Most of Sika's self-levelling products are silane terminated polymers. I have used their concrete formula.........on concrete. Works very well there, but I would be extremely hesitant to use for any other purpose.