Caulking and Sealants (silicone, parbond, vulkem & more)

[ROBERT CROSS]

What is this grey stuff around the vent?

[Inland RV Center, In]

Originally Posted by poison dwarf

yo andy (yoda)any chance i can buy some vulkem and parbond asap ,going away in 3 weeks. when i got my 290 it had been in a hale storm in usa and leaks real bad over my kids bedroom (rear bedroom).I now have new baby making 3 and my wife keeps giving my **** as she would have liked to have brought a hymmer (real ugly english camper )not rv.please could you put me in touch or help me get some quick.thanx dude may the force be with you.

Check your PM.

On small items, we can ship same day, if the order is placed before 2 PM Pacific time.

Andy

[BeckyAnt]

Just had three days of rain and found out the vista window in the roof of our "new" 1974 Sovereign is leaking badly...we're planning to polish the outside of the AS within the year, and possibly take out the windows to get the old tint off, so we don't want to do anything permanent, but definitely want to stop the water. Would clear silicone caulk work as a quick fix? We won't be moving the AS, and we want something we can peel off pretty easily when it's time for window work.

Also have a leak somewhere in the roof...I think it's either from the vent or the air conditioner...it's slowly dripping through the seam in the ceiling but the gasket around the vent is dry (from the inside) and there doesn't seem to be any water in the AC. Again, ok to use silicone, or should we use vulkem?

Thoughts?

[Krazyjohnny]

Inland Andy and Happy Campuer,

I just got an e-mail from Tim Maxwell of Airstream about the sealants needed for my 07' 27'FB. I know you are wondering why I would even be bothering with that, but I have a leak in my "no fuss flush" line and will need to remove the connector from the side of the trailer. With that in mind I will then need to re-seal this when I am done. He e-mailed me a list of products from Sika that they use at the factory.

Sikaflex 221 in grey and Black for around interior segment seams and the black for around all Safari Hehr windows.

Sikaflex 721 UV in Gray and White for around all extrior components.

Acryl-R Seam Sealer for all segment seams, clearance lights, main door, beltline, rub rail, and screen door.

Am I going to be buying a substandard product by notusing the Tempro stuff? Be objective Happy Campuer.

[HappyCampeur]

Originally Posted by Krazyjohnny

Inland Andy and Happy Campuer,

I just got an e-mail from Tim Maxwell of Airstream about the sealants needed for my 07' 27'FB. I know you are wondering why I would even be bothering with that, but I have a leak in my "no fuss flush" line and will need to remove the connector from the side of the trailer. With that in mind I will then need to re-seal this when I am done. He e-mailed me a list of products from Sika that they use at the factory.

Sikaflex 221 in grey and Black for around interior segment seams and the black for around all Safari Hehr windows.

Sikaflex 721 UV in Gray and White for around all extrior components.

Acryl-R Seam Sealer for all segment seams, clearance lights, main door, beltline, rub rail, and screen door.

Am I going to be buying a substandard product by notusing the Tempro stuff? Be objective Happy Campuer.

You can't go wrong with Sika. They are a serious company.Mostly known for their cementous product but good quality sealant as well. If the AS factory use it and they don't have problems with it, i say go ahead!! If your AS would have been older (Tremco products on it) i would advise you to stick with the same manifacturer ..(Compatiility issues). Hope that helped...

[Krazyjohnny]

Thank you for your quick response. I will hunt this stuff down like a rabid dog now.

[neil.ervin]

Andy often talks of using Vulkem on window tops and parbond on the window sides/bottoms. My 2005 Safari's windows are held in place by a heavy black rubber molding, all around. The space between the aluminum frame and the molding is the same all around the window (very small break, much less than 1/8"). Why shouldn't I use Parbond at the window top too?

When applying a sealer to this type of molding, should I try to pull the rubber moulding away from the aluminum frame and insert sealer under the molding lip?

Thanks,
Neil
Sequim, Washington: on the beautiful Olympic Peninsula

[connorsa]

Andy, I couldn't help it. My big front window leaked during a bad storm was up from 2 a.m. sopping up the water coming in at the bottom of the window. Made a made dash to Home Depot that next morning, bought 4 tubes of clear silocone window caulk and caulked all around the window inside. Today after it's dried, I did the outside. I didn't know what else to do.

Thanks, Anne

[Inland RV Center, In]

Originally Posted by neil.ervin

Andy often talks of using Vulkem on window tops and parbond on the window sides/bottoms. My 2005 Safari's windows are held in place by a heavy black rubber molding, all around. The space between the aluminum frame and the molding is the same all around the window (very small break, much less than 1/8"). Why shouldn't I use Parbond at the window top too?

When applying a sealer to this type of molding, should I try to pull the rubber moulding away from the aluminum frame and insert sealer under the molding lip?

Thanks,
Neil
Sequim, Washington: on the beautiful Olympic Peninsula

Yes, but carefully.

Andy

[Inland RV Center, In]

Originally Posted by connorsa

Andy, I couldn't help it. My big front window leaked during a bad storm was up from 2 a.m. sopping up the water coming in at the bottom of the window. Made a made dash to Home Depot that next morning, bought 4 tubes of clear silocone window caulk and caulked all around the window inside. Today after it's dried, I did the outside. I didn't know what else to do.

Thanks, Anne

Anne.

Remove all the silicone as soon as possible.

It should never be used on the exterior.

The silicone sealer will discolor and attract dirt like a vacuum cleaner, that will look terrible.

There is a silicone residue cleaner available that will help.

Only then, can you attack the real water leak.

In the future, always carry some "duct tape" with the trailer. While it may look ugly, it is a great temporary help for water leaks, etc.

Andy

[BeckyAnt]

Hi, Andy,

What's the silicone remover called? I am pretty sure the sealant on parts of the outside of mine is silicone. THANKS!

[Roadrunner]

I understand the importance of having a clean and dry surface for use of parabond/vulkeme...but I need to seal some areas on our "78" ambassador and it is cold here in the Northeast. Does anyone know what the working temperatures should be when applying either of these? Thanks!

Bob

[connorsa]

Came home last night and the RV park was flooded. The water in front of the office was above my Jeep door. I managed to make my way to the creek and over the high bridge with 4" of water running over it and back to the space where my A/S was parked. Hallelujah she was not flooded, though the high water was making it's way to her quickly. The rain slowed down an hour later and began to recede. I was incredibly grateful. And I was so grateful for my silocone as the inside was dry and warm. It's all relative. You do what you have to do, where you are and for that season.

Anne

[silverleeper]

Originally Posted by BeckyAnt

Hi, Andy,

What's the silicone remover called? I am pretty sure the sealant on parts of the outside of mine is silicone. THANKS!

This is an example. Silicone Caulk Remover

[Fyrzowt]

I don't know enough about silicone to speak intelligently about the properties of it. In the past I have blindly bought off on the "No Silicone" mantra. It appeares that there are a couple of types, and that one type is acceptable/recommended for external use with aluminum and glass, etc.
The information below came from a professional construction website, it was posted by someone recognised as an industry expert. I'm willing to have an open mind and learn more. If you have factual info, by all means post it.
If there is too much detail for you, skip down to the conclusion paragraph.
Dave

Here is the info he provided:

This page examines the properties of Silicone sealants commonly used in the installation of Windows Doors and Conservatories.

There is much confusion about different silicone types, and not surprisingly, as their descriptions give little in the way of clues as to the correct grade and type for a given application, and there is no one single type of silicone sealant that should be used for everything.

Joint failure - the most common causes:

* The wrong silicone was used.
* The joint width and/or depth was too great or too small.
* Excessive movement in the joint sealed.
* Contamination of surfaces - 'dirty' materials.
* Poor gunning and application technique.
* Poor quality sealant.

It is important to consider all of the above when sealing a joint, and in particular to make sure that the surfaces are clean and that all protective tape is removed and that there is no residue. Deep or wider than normal joints should be filled with foam packer rod.

Silicone types in common use in our industry include:

* Neutral cure - Acetoxy cure
* High Modulus - Low modulus

Is there much difference, and does it really matter?
The answers to these two questions are Yes, and Yes.

The cost difference between low modulus and high modulus is not much, but the cost difference between Acetoxy cure and Neutral cure (dearer) can be quite a few pence a tube, and as many in the industry seem to think that 'it is all the same', some are often repeatedly using the wrong type of silicone for the job.

Modulus explained:

Silicon sealants are classified for use in either a) glazing joints, or b) for building joints other than glazing. There are further classifications to do with how well the movement capability is accommodated. The movement accommodation of the higher % ones (20%+) are then classed into low modulus and high modulus.

The meaning of high and low can be explained simply: a low modulus will need just a low force to stretch it, and will have better elasticity and movement accommodation, and a high modulus is more rigid. In deciding which modulus is best for a given application, then desired movement accommodation is the main thing to take into consideration. In our industry it is generally accepted that linear expansion and contraction of the plastics we use, as well as joint movement itself, can be reckoned to be high, therefore a low modulus silicone should be used to accommodate such expected movement. Some of the better silicones boast being able to accommodate movement of up to 50% of the nominal joint width.

Cure explained:

The words 'Acetoxy' and 'Neutral' cure give no clues as to which is right for what job. In a nutshell the type used will determine how well it will adhere to the materials is is used on. If you have seen silicone that almost peels off on it's own, but then at other times it seems hopeless trying shift the stuff without a silicone remover chemical, then here is why:

These (meaningless for many) names derive from the curing system, and from the by-products that are emitted as the silicone is curing, i.e.

* Acetoxy silicone sealants release acetic acid (which smells a little like vinegar) as they cure.
* Neutral (meaning neutral alcoxy) silicone sealants release alcohol as they cure, and has almost no smell.

Acetoxy cure.

This is the most commonly used (maybe out of ignorance, or because is cheaper?), it is more rigid and the full cure is quick. On the downside it generally has poor adhesion and leaves much to be desired in how well it 'sticks' to PVC-U, most other plastics, and glass, aluminium and Polycarbonate. Shrinkage can be acceptable if it does not contain added solvent. I have heard that the chemical released with Acetoxy cure attacks and degrades polycarbonate in some way.

Neutral cure.

Much better adhesive properties for a greater number of materials including PVC-U, most other plastics, glass, aluminium, lead, stone and masonry, and Polycarbonate, it cures with atmospheric moisture and skins over in about 30 minutes, and leaves a shinier finish. On the downside it is more expensive, and is slower to cure at one to five days depending on thickness, temperature and humidity conditions.

Conclusion:

The benefit of using a good Low Modulus Neutral Cure Silicone can be summed up thus:
It offers high movement accommodation and excellent adhesion to almost all building and glazing materials, without any of the unwanted 'side effects' Acetoxy could possibly cause.

If you want to be using a silicone sealant that will accommodate the movement of plastics to other materials as it should, AND a silicone that is going to 'stick like billy-o', then it is Low modulus, Neutral cure for you from now on. The worst you can use would be High Modulus Acetic cure, because although this would seem to initially adhere, it will not be long before it (and maybe you) quickly becomes unstuck. Just to complicate matters Acetoxy cure in low modulus is available.

Suppliers will often say "how much are you paying for silicone" when they are trying to sell to you, but just make sure that they are quoting for neutral cure, and if you are in our industry and have always used Acetoxy cure, 'because it's all the same, innit' - then stop, and start using the right stuff, Neutral cure - and low mod.

Tip: When you compare makes of silicone/prices, have a look to see if the movement capabilities listed on the tubes are better or worse, expressed as a %, because some sealants are 'bulked out' with fine chalk powder etc., to make a cheaper but inferior product. Not so many tubes seem to display the movement capability as often as I remember, but you could always seek out a manufacturers data sheet. The downside of using a silicone which has been 'bulked out' is that as well as a higher than desired shrinkage when it has cured, you could get discolouration, and poorer adhesion.
© 1998-2009 TheWindowMan.co.uk - Quotatis Ltd - All rights reserved

[airdreamers]

Does anyone know what the overlap of aluminum is at the seams thoughout??

[Inland RV Center, In]

Originally Posted by airdreamers

Does anyone know what the overlap of aluminum is at the seams thoughout??

You can measure the overlap on your side sheets.

The bottom sheet on each side is 30.5 inches wide.

The window and roof sheets are 56.5 inches wide.

Generally speaking, the segments overlap about 3/4 to one inch or more, depending on the exact location.

If you measure 29 inches on the lower panels, as an example, then your overlap would be 1 1/2 inches, which is about correct.

You will need to remove the rub rail at some small place to see the bottom of the lower side sheets.

Andy

[Globie64]

I was dismayed to find yesterday that our skylight was leaking again. I had used Sikaflex to seal it about 4 years ago, and the stuff stuck well except for a place where it was kind of thin. I dug it all out and will start again, but am wondering about metal prep, without reading through all of the thread, to find a favored product.

I also had an interesting experience with silicone that had been gooped around the rear roof vent- it was leaking between the frame and the skin. The silicone just pulled right away, and I replaced it with urethane caulk, a temporary fix until I get some gray Sikaflex. A couple of years ago, I had very neatly caulked the whole trailer with GE Silicone before reading about silicone and aluminum. I proceeded to strip the whole thing and clean off the silicone residue, and caulk with Sika. Thing is holding tight, even after a huge downpour last night.

[Globie64]

NOW I see the "silicone caulk remover". Thanks!

[Lance M]

I purchased these two sealants from Fastenal a few weeks back. Has anyone ever used the 3M 560 polyurethane adhesive sealant? It was a bit expensive at $15 per tube. The Tempro 626 is supposed to be like Vulkem 116 but has less work time. I have been using the Sikaflex 221. It has a nice finish to it. I don't dig the texture of vulkem.