What sealant is used on new travel trailers

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x94cherry

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Hi everyone--I'm new to RVing and just bought a four-year-old Gulf Stream Vista Cruiser (fiberglass walls and roof).

It appears that the whole thing (except the roof) has been re-sealed with clear silicone. I didn't think anything of it because the RV dealer recommended silicone as a sealant, and because all the trailers we looked at, including the new ones, were sealed with a clear sealant that looked and felt like silicone. Now, though, I'm learning that silicone sealant is a big no-no with RVers.

So I'm curious: were all those new RVs we looked at sealed with silicone, or is it another sealant that looks like silicone but isn't? If it isn't silicone, what is it?

Also: Why do all the RV dealers sell so much silicone sealant if it's that bad?

Also: How concerned do I need to be about the silicone sealant on my trailer? It looks like it's mostly in good shape. Do I need to scrape out all that silicone and re-seal it with something else?

Thanks in advance for your help!
 
On our Winnie, silicone is used to seal the exterior porch light and area-light on the driver's side, but butyl tape (or something similar) is used around the door and window frames. I think that's pretty typical. Winnebago provides a list of sealants they used in different places throughout the coach, but I don't remember, off hand, if they used it anywhere else.

I won't use silicone to seal anything on our coach unless it's already been used. It seals well, and seems to be fairly durable, but it's incredibly difficult to completely remove, and nothing else will stick to it.

Kev
 
Now, though, I'm learning that silicone sealant is a big no-no with RVers.
Click to expand...
That is false, incorrect info that has been spread willy-nilly on the internet. Silicone is definitely NOT recommended for sealing roof seams but has its uses elsewhere and most RVs come from the factory with at least some silicone caulk.  Window frames is one common use.
Further, not all silicone-based caulks have restricted uses; modern sealant/caulks are often a silicone-acrylic blends that do not have the oily residue that makes pure silicone a poor choice for some purposes. If the sealant is labeled as being paintable, you can be sure it safe to use on most any joint.
All that said, there are excellent clear sealants that are great for RV use. Geocel Proflex RV is one of them, but there are other brands and formulations that work well too. 3M Body Seam-seal is another.
 
Thanks, everyone, for your insight. Looks like this is a pretty hotly debated topic. I guess I'll live with my silicone seals for the time being, maybe I'll replace individual seams with something else as the silicone fails over the years.

"RVer emeritus," nice.
 
Since the stuff is already on there, "wait & see" is your only option.  There is no value to trying to replace it before something else makes it necessary.  Let me be clear: There is nothing wrong with the sealing action of silicone.  The issue with pure silicone is that any future repair of the sealed joint requires removal of the old silicone first. That's a fair amount of extra work on a rubber roof seam (making it a poor choice there), but trivial on a window frame or other joint that requires only a slim bead and is on a surface that is readily peeled and cleaned with mineral spirits or similar solvents.

Sorry if I appear to be ranting from a soapbox. I do get a bit vocal when I encounter internet myths that are just plain wrong and cause needless worry or work among folks like yourself.
 
Gary RV_Wizard said:
Since the stuff is already on there, "wait & see" is your only option. There is no value to trying to replace it before something else makes it necessary. Let me be clear: There is nothing wrong with the sealing action of silicone. The issue with pure silicone is that any future repair of the sealed joint requires removal of the old silicone first. That's a fair amount of extra work on a rubber roof seam (making it a poor choice there), but trivial on a window frame or other joint that requires only a slim bead and is on a surface that is readily peeled and cleaned with mineral spirits or similar solvents.

Sorry if I appear to be ranting from a soapbox. I do get a bit vocal when I encounter internet myths that are just plain wrong and cause needless worry or work among folks like yourself.
Click to expand...
So are you saying that if I use the 3M Body Seam-seal I won't need to remove the old sealant and I can apply it directly after giving it a good cleaning? I am noticing some cracking of the old sealant that goes around my tail lights
 
I'm not sure I'd use the 3M seam sealer. I believe that that product is designed to be painted over and will not stand up to the UV light if used unprotected.
For the roof, I wouldn't use anything but Dicor.
 
memtiger said:
So are you saying that if I use the 3M Body Seam-seal I won't need to remove the old sealant and I can apply it directly after giving it a good cleaning?
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I did NOT say you can use the 3M over existing pure silicone. Nor the Geocel either. Once somebody has applied pure silicone, it has to be removed before applying a new coat, whether more silicone or something else.
Old_Crow said:
I'm not sure I'd use the 3M seam sealer. I believe that that product is designed to be painted over and will not stand up to the UV light if used unprotected.
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The 3M Flexiclear Body Seam Sealer product is designed for visible seams and is a non-yellowing formula. It specifically says for use where it will not be painted. Other sealers in the 3M Body Seam Seal family of products may differ (I don't know but the specs are avaiable online if you care to look).
 
I use a product that I get from Amazon called Alfa Seal. This is what Grand Design uses at the factory. It is good on EPDM roof. I get the clear for everything except the roof.
 
I think you mean Alphaseal, a line of sealant products from Alpha Systems that is now marketed thru Lippert. Alpha is the main competitor to Dicor in the EPDM roof membrane business and is the OEM roof membrane and sealant used by some RV manufacturers.

Alpha makes both vertical and horizonatl (self-leveling) sealants and also a roof seal tape called Alphabond.

RV Sealants & Adhesives | Alpha

Get more out of your RV sealant! Formulated to withstand harsh-weather environments and flexible enough to absorb the shock, vibrations and stresses of the road, Lippert RV sealant gives confidence for the road ahead. Sealing your RV for adventure just got easier.
store.lci1.com store.lci1.com
 
Uncledave54 said:
Thanks for the response.

What I'm finding on multiple review websites is it should only be used as a temporary fix.
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Anything overly advertised on TV is likely garbage. Flex seal is more expensive per foot so there is no reason to buy it unless you need a midnight repair and Walmart is the only place open.
 
I used quite a bit of Dicor both in the self leveling and non-leveling variety, in addition to Butyl tape under vent flanges and such during installation. However I kept reading recommendations for Geocel and bought a tube to try on a small job I had and I am sold. Its the non-leveling variety and I sealed around the new water fill door/frame I installed and it looks much nicer than the Dicor and I suspect seals better too. To me, silicone is something to be avoided as it causes problems with removal and resealing down the road.

Winnebago even publishes a sealants and paints manual to assist motorhome owners with using the right stuff in the right places on their products.

Charles
 
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