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Davydd · 09-08-2003, 08:01 PM

Vulkem is a Tremco Company polyurethane sealant that is applied with a caulking gun. Someone mentioned Sikaflex, which is Sika's polyurethane sealant. There are several companies that produce polyurethane sealants.

Tremco lists about a half dozen different Vulkem products. They all come with a standard aluminum color amongst many other standard colors.

In looking at the different Vulkems it seems Vulkem 931 may be the best choice. It is a one-part non-sag sealant suitable for moving joints and vertical applications. It has a very fast drying time and good adhesion to aluminum. It's hardness is about average among the Vulkem products. Tremco also has Vulkem products suitable to be immersed continuously in water. This feature is the main selling point of the product.

One part Vulkem products come in tubes. There is also a two-part polyurethane Vulkem 222 but it comes typically in 5 gallon pails and must be mixed before use. I doubt no one but a sealant professional would want to tackle that and 5 gallons is way more than you would ever need.

Vulkems may have evolved over the years. It is hard telling what the older Airstreams actually had. I do know that polyurethanes have a useful life of about 10-15 years in building joint exteriors but we are talking about sealant joints that fill gaps from about 3/8" up to 2".

Silicone sealants have a theoretical longer life than polyurethanes. Typically 20 years. They are just as suitable in my mind. These kind of sealants didn't exist when vintage airstreams were being built.

Whether you use polyurethane (Vulkem) or silicone, you should thoroughly clean the joint down to bare aluminum.

Don't use acrylics, polyvinyls, or modified silicone acrylics--all typical stuff you can buy retail at Home Depot. To get the right stuff you may have to go to a commercial builders supply store.

That's my 2 cents today.

53flyingcloud · 09-09-2003, 05:07 AM

thenewkid64

Quote:

Some members transfer some to a large volume syringe to have better control over the bead size when sealing smaller seams. I can understand this as the par bond seems to develop a hard cracked finish look as it ages. The Vulcem stays soft and finished the way it was when you left it.

So very true~!

This is the easiest way to control your flow..
The syringes can be bought from: Airstreamdreams

As best I can recall, the prices was well under a dollar per unit. The secret to controlling the flow is all in the cut. You should try to cut the tip of the syringe at a 45 degree angle and, make it as small or large as you need for the job.
Plus..keep this in mind, you can reuse the syringe numerous times with proper storage or cleaning, if you'd just clean it out after you're done.
Good luck~!
ciao

stellablu · 09-09-2003, 11:03 AM

Thanks all. I tried a little syringe I have from the baby's medicine and it still is a pain to do. Maybe someone can show me at a meet or something.

So - masking tape would be good, then do you make it flush with the skin by dragging a blade over it?

I think I need to contact a Chicago area person to show me how to do this before I ruin my trailer's skins!!!! Right now it doesn't really leak - except by two windows so it might hold till next year???

Stellablu

TOM CRUMP · 11-01-2003, 06:51 PM

Helping a friend with some fix-up on his '84 34' excella (in exchange for borrowing priviliges) The big stationary window left of door taking on water between panes, caulk on entire coach in bad shape, Questions: What is best tool for removing old caulk? Is there any way to get rid of the water? Is water getting in from some way other than bad caulk? Going with the Vulkem caulk, probably using acetone to get all residue. Yor replies are greatly appreciated, Tom

dscluchfc · 11-01-2003, 07:06 PM

My same window has fog in it too. I know you can take them out and reseal them, but I have not attempted it.
When I got my 84 Excella 31 ft, there was a number of leaks.... around the running lights, and tail light assemblies, and also where the ZipDee awnings were screwed into the skin.
I used ParBond aluminum caulk on all these spots. No more leaks. I used a metal awl type tool to remove the old dried up material which also appeared to be ParBond. Then reapplied ParBond. It flows very smoothly and nicely.

Joe Z · 12-05-2003, 09:25 PM

I am stripping and replacing the Vulkem above the windows and door and have run into one problem - after removing the majority of the caulking there is still a thin, hardened layer in some areas that will not come off. I'm sure I could use some type of solvent or a metal scraper to get it off (wood & plastic don't work here) but don't want to damage my clear coat. Any suggestions?

Navigator · 12-06-2003, 03:20 AM

I Wound up using a hot knife.

53flyingcloud · 12-06-2003, 03:50 AM

This is by no means all inclusive but...One of the neatest lil tool I found for working around the windows, etc is a "stainless steel" tooth pick that I picked up from Wally's World..What's nice about this is that because of it's small size and, hook feature..it allows you to work into tiny gaps..Just be real careful not to scratch your skin's surface..

Now you know another trade secret...lol

ciao

john hd · 12-06-2003, 04:36 AM

this may not work for you....

when replacing some sewer vents on a buddys trailer i used a brass wire wheel chucked in a drill.

takes all traces of vulkem right off! and everything else. it leaves a nice burnished surface.

obviously, this will not work if you are trying to save the clear coat. the wire wheel is better suited for areas that don't show or in preperation before polishing.

i also used it to clean the vulkem from the tops of windows before resealing.

john

Dwight · 12-06-2003, 05:07 AM

Try Hoppe's No. 9 Solvent. It works extremely well and you can get it at Wal-Mart as well.

j54mark · 12-06-2003, 07:40 AM

Mineral spirits (paint thinner) will work, albeit slowly. Use a craft stick sharpened like a chisel to speed removal.

Mark

uwe · 12-06-2003, 08:00 AM

How about a tiny brass wire wheel in a Dremel type tool?

Sneakinup · 12-06-2003, 08:44 AM

I removed mine with a wire wheel in my RotoZip tool. It worked great, with a few cautions. WEAR GOGGLES!!! Also, the Vulkem gets heated and flies all over the place, then cools, and is tough to remove from everything. In addition, the wire wheels tend to disintegrate quickly. At $3+ each, it adds up quickly.

Other than that... it does work well.

Sue&Von · 12-29-2003, 02:19 PM

We are beginning to research sealants in our own plodding way. There is so much on this subject to plow through.
As well as finding where to buy the products we choose finally.
Lots is here lots probably over at VAC list or whatever they changed it to, and probably lots at all other Airstream sites.
Then there are the manufacturers sites etc.

Gonna check with wholesale suppliers and glass companies and anyone else I can find.

Von seems to remember a body shop pro telling him years ago that silicone contained sodium (SALT that is) and for that reason it should never be used on metal. We don't know if that is accurate or not, but it stuck in Von's mind all these years. Do any of you know?

What if any knowledge does anyone have regarding applying heat ....flame or hot air to the old existing sealants to help with removal. We of course can appreciate the Safety risks. It is the removal data we seek.

TYIA
$&V

ALANSD · 12-29-2003, 04:07 PM

Vulkem stays soft? I used it around trim work on my motorhome a year or so ago. It has gotten dirty looking , and seems to hold onto black moldy tree stuff that is hard to get off.
I also used the "aluminum sealant" from HD around some windows, and it is still silver and shiny. So whats wrong with the aluminum stuff?
Looks good to me for trim work, although I would use the Vulkem for larger apps like around the TV antenna, etc.

Davydd · 12-29-2003, 05:50 PM

We use silicone construction sealants for metal to metal contact all the time. Generally it is used with sheetmetal, aluminum entrance frames, glazings, etc. I never heard of salt being an ingredient of silicone sealant or silicone being a detriment to metal. Metal is what it is primarily used for.

Davydd · 12-29-2003, 05:55 PM

I forgot. You might want to ask on what authority? OK, I am an architect registered in 11 states, a certified construction specifier, and responsible for architectural document production and quality assurance for about 3 billion dollars of construction per year. I better be right in what I said or I am in big trouble.

Besides, the American Institute of Architects' Masterspec documentation backs me up.

wahoonc · 12-29-2003, 06:03 PM

I was always taught not to use silicone and silicone base caulkings on mill finish aluminum because of the acetic acid. I work with architectural metals and NONE of our manufacturer's recomend or specify silicone caulk. Butyl, Polyurethane, Terpolymer, Rubber but not silicone. From what I have observed in the field, silicone does not adhere well to very many smooth surfaces, just got done peeling about 5 tubes worth of silicone off of the windows of my AS, considering the fact that I used my finger nail to pick at it and it just peels right off, I don't think it adheres well at all to smooth surfaces.

Aaron

aviontt · 12-29-2003, 06:41 PM

Well this just gets more difficult every day I'm watching this thread to get some info but I keep getting bushwacked...What is the best stuff ? and what is the best way to apply it ? HEEEELLLLP !!!!!

wahoonc · 12-29-2003, 06:50 PM

Quote:

Originally posted by aviontt
Well this just gets more difficult every day I'm watching this thread to get some info but I keep getting bushwacked...What is the best stuff ? and what is the best way to apply it ? HEEEELLLLP !!!!!

aviontt,

The two types of caulk reccomended by AS are the Vulkem and Parabond, as far as the application use common sense as well as trial and error

Aaron