Silicone caulk on aluminum

[sunny75]

Hi there,
I'm relatively new to this too (just got our 75 in April), so I'm not an expert on fixing leaks. All I know is that I spent a lot of time this spring trying to remove pounds of silicone caulk from around every rivet and seam so I could polish the trailer. It was really hard to remove and something in it eats the aluminum. Most Airstreamers don't have a problem with Vulkem so that is what we are using. Good luck!

[Alumaholic]

There, it's been said again for about the 999th time on these forums.
You can trust a sales rep who has no direct experience, or you can trust fellow Airstream owners who care about your investment and who:
- Have direct experience
- Have extensive training in caulks and sealants and their applications
- Have owned and restored multiple Airstreams
- Have spent many long and tedious hours removing silicone caulk
- Have declined to purchase Airstreams where silicone caulk was used by POs.

There are several great choices out there for different caulking applications on your Airstream. I am not going to reiterate all the good information. "Lewster" has some good advice as do others.

To quote "Wahoonc"..."Vulkem/Trempro or equivalent sealants from Sonneborn or Sikalastic are much easier to remove and reseal when the need arises."
Add Sikaflex to the list. Other urethane based caulks may also be used. (Yes, Tremco makes urethane based caulks. I'm surprised Lyn Dickinson didn't mention this alternative.)

[aftermath]

Take away the issue of using silicone with that acid that "eats" aluminum, what is the real drawback? From what I read it has more to do with how the silicone was applied. Most complain about smeared silicone covering seams and goops of the stuff that is very difficult to remove. Isn't it a good thing if it is difficult to remove?

Suppose you use a good quality silicone that is formulated for aluminum and you applied it with care and precision, what would be the problem? I am in the ongoing process of resealing my trailer and I am using sika-flex as per advice from our local dealer. I have no complaints with this product but I am starting to question all of the criticism of silicone I am hearing. Remember, there is more one way to skin a cat (whoops, bad analogy), cook a turkey (?), mow the lawn.........you get my idea.

[Someday'59]

So, another thing about silicon is that dirt sticks to it. The dirt sticking to it... it may or may not be a big deal to you. For me, it was a big deal. It made our trailer look gross.

[Ganglin]

Originally Posted by Someday'59

So, another thing about silicon is that dirt sticks to it. The dirt sticking to it... it may or may not be a big deal to you. For me, it was a big deal. It made our trailer look gross.

If you've ever used TremPro 635 (vulkem), and have to work outside, it takes forever to set up and every piece of dirt, dust, etc. in the air stick to it permanently. 116 sets faster but still does the same thing - they are all very sticky sealants before they set up, including silicone.

[Someday'59]

Stuff stuck to the silicon after is was set up, too. ick!

[Ganglin]

The TremPro I used on my windows does the same. It takes on dirt and pollutant stains and requires a focused scrubbing to make it look decent.

It's been there 4 years now and is starting to crack and craze already. That will make it harder to keep clean. As I said in a previous post on this topic - I used it once, so I know what the results are, and I'll never use it again.

I have better things to do than replace sealant every 4 or 5 years.

[Aage]

Originally Posted by aftermath

Take away the issue of using silicone with that acid that "eats" aluminum, what is the real drawback? From what I read it has more to do with how the silicone was applied. Most complain about smeared silicone covering seams and goops of the stuff that is very difficult to remove. Isn't it a good thing if it is difficult to remove?

But isn't that like saying if your car has no gas in the tank, you won't have a traffic accident? I mean, the fact is, it DOES attack the aluminum. I want to say that it's acetic acid which does the bad stuff, but I won't swear to it.

All I can say for sure is that on my trailer, where the PO used silicone (mostly around windows), the silicon went either black or green as it aged. I don't know if that is a result of bad application technique or not, and frankly I don't care. The simple fact that it is so difficult to remove is PLENTY for me to stay away from it.

[aftermath]

Aage, I was going by others have said about the silicone formulated for use with aluminum, the kind without the acetic acid. Again, if this product is out there then the argument against it eating the aluminum is void.

I have not used any of this on my trailer so I can't speak with any authority.

[Alumaholic]

Cured silicone caulk attracts dust.
Almost all caulks must be protected from dust, blowing sand, kitty hair, etc. before they dry.
But silicone attracts dirt after it dries.
The wider the bead, the uglier the dusty strip.
I'm not sure why dust adheres to silicone more than urethane based caulks, but it does.
On a related note, I spent big $$ on replacement windows for my home in Albuquerque. The installer fastened the trim around every window with silicone adhesive. After a couple years of dust collection, the window trim looked terrible. It cost me more big $$ and much stucco damage to have the silicone removed. After a whole house re-stucco, a real expert on coatings and sealants sealed the joints where window frames meet stucco with architectural quality, varathane caulk.

[cameront120]

Originally Posted by Alumaholic

After a whole house re-stucco, a real expert on coatings and sealants sealed the joints where window frames meet stucco with architectural quality, varathane caulk.

I'm assuming you mean urethane?

[Alumaholic]

Originally Posted by cameront120

I'm assuming you mean urethane?

Varathane is a name brand description of generic urethane. My mistake.

[cameront120]

When I see Varathane, I think wood finish.

[girlscan2]

Like with the trailer hitch threads, the caulking threads have me totally confused. http://www.airforums.com/forums/f456...ure-87316.html

I'd like to use what works best and do it once (at least for the forseeable future.) I'm thinking I may have some silicone to remove at the rear. I have matching dents on both sides of the rear with a leak on the right. I was hoping just to stop the leak and not get into a remove and reinstall process but I'm willing to do it right once if I can figure it all out.

If I were to purchase McKanica Silicone Caulk Remover Gel (as recommeded above) how much do I need (how far does one tube go?) Have others used this with good results or is there a better product???

Thanks!

[Ganglin]

This should give you an idea how far a supply will go.

Silicone Caulk Remover

Originally Posted by girlscan2

Like with the trailer hitch threads, the caulking threads have me totally confused. http://www.airforums.com/forums/f456...ure-87316.html

I'd like to use what works best and do it once (at least for the forseeable future.) I'm thinking I may have some silicone to remove at the rear. I have matching dents on both sides of the rear with a leak on the right. I was hoping just to stop the leak and not get into a remove and reinstall process but I'm willing to do it right once if I can figure it all out.

If I were to purchase McKanica Silicone Caulk Remover Gel (as recommeded above) how much do I need (how far does one tube go?) Have others used this with good results or is there a better product???

Thanks!

[tkasten]

I've used McKanica Silicone Caulk Remover Gel with good results. I purchased the 8 oz. cartridge and glad I did as I needed to go over a few spots a couple of times. IMO the key to success is to spread it over the silicone w/finger (use glove) and give it time to work a day or more. I had some left over so I taped up the end of the tube and put it in the freezer with my left over Tempro.

[sunny75]

I spent days removing silicone this spring and never found the magic remover. The most effective strategy I found was to use the Aircraft Remover (a Rustoleum product) that I also used to strip the clearcoat. The spray is especially lethal with sunshine heating up the aluminum. It literally sizzles! Repeated applications and the rubber scraper and a lot of elbow grease eventually did a pretty good job of getting most of it off. Be persisitant. I'm happy with the results and with the caulk residue left in the seams, we have no leaks!

[girlscan2]

Thanks Ganglin, Tim and Sunny! More projects for a sunny day (which we have plenty of here.)

[Dwellstream]

I am in the glass & glazing business and most of the shops, at least in the southeast, stock and use Tremco Dymonic polyurethane. I checked what we have in stock today, and it is FC for fast cure.

We stock RTV (room temperature vulcanizing) silicone which has no acid. You might check with the local glass shop in a pinch. Most towns have one.

[Aage]

Odd how close that is to the name of the most popular sealant used on Airstream trailers: Trempro (formerly Vulkem). Trempro 635 is one variation; it comes in different colours.