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Roof sealants

Yahoo Message Number: 26596
It seems as if Dicor is only used in conjunction with EPDM rubber roofing projects.

The Acryl-R product limitations include: do not use with polycarbonate or acrylic surfaces due to crazing?

Will the experts out there please comment on this? Thanks

Ron 98 Allure 30185

Re: Roof sealants

Reply #1 –
Yahoo Message Number: 26619
Quote from: Ron Schonscheck\[br\
] >

It seems as if Dicor is only used in conjunction with EPDM rubber > roofing projects.

The Acryl-R product limitations include: do not use with
polycarbonate

Quote
or acrylic surfaces due to crazing? >

Will the experts out there please comment on this? > Thanks

Ron 98 Allure 30185
I was considered an "expert" at one time. In the state of California I was a sealant contractor for 25 years. My expertise goes back about 8 years now. Because of increasing enviromental restrictions many sealant products are less durable today than years ago, but more user friendly.
Acryic based sealants used to be used mostly for vertical applications only, if they are immersed long term they turn to mush. On a flat roof in winter, depending on rainfall and wind direction they could be wet for extended periods.

I would recommend a low modulus polyurethane sealant, and a slope grade, (not a flow type) would be easier to use. A caulking and sealant supply company would be a good source.
Good manufacturers used to be Sika corp. Mameco and Tremco. Home depot carries Mameco Vulkem 116 last time I checked, which would be good for anywhere that has low movement, such as around roof penetrations.
I am going back to the SF Bay area this week and visiting with friends that are still in the sealant business, so I will update this next week with current products and sources for anyone interested.

Chris Bradley
Affinity 4952

Update on Roof sealants

Reply #2 –
Yahoo Message Number: 26773
Hi All,

After doing a little research, the best sealant I have found that is easily available (Home Depot at $10.75 a 10oz tube) is 3M 5200 Marine Sealant. Available in white, and recommended by the manufacturer for use on fiberglass as well as most other surfaces without a primer.

It holds up long term to extreme weather and continuous immersion even in salt water. The consistency is a very soft gun grade, and it has a very long working time of 3 to 4 hours, tack free in 24 hours, full cure in 5 to 7 days. They also make a fast cure 5200 that is tack free in 1 hour with a working time of a few minutes, but this would be special order.

Application.

After cleaning up or removing the old sealant, tape with 1" masking tape around the area to be sealed about 1/4" to 1/2" wider than the previous material so we get a bond to a new untouched part of the roof, the same on the skylight or pipe. After laying down a bead with a caulking gun, spread the sealant with a small trowel or round ended knife to cover the joint. Pull the tape after you are satisfied with the job. The 5200 comes in aluminum tubes so any partial tubes you have left over after the job will last a long time before setting up in the tube. Figure you will get about 10' to 15' feet out of 1 tube.

Be careful about getting this caulk on clothes or making a mess, it does not clean up!

Chris Bradley
Affinity 4952

Quote from: Chris Bradley
[quote author=Ron Schonscheck

>

> It seems as if Dicor is only used in conjunction with EPDM

rubber

Quote
roofing projects.

> The Acryl-R product limitations include: do not use with
polycarbonate

> or acrylic surfaces due to crazing?
>

> Will the experts out there please comment on this?
> Thanks

> Ron 98 Allure 30185
>

I was considered an "expert" at one time. In the state of

California I

Quote
was a sealant contractor for 25 years. My expertise goes back

about 8

Quote
years now. Because of increasing enviromental restrictions many

sealant

Quote
products are less durable today than years ago, but more user

friendly.

Quote
>

Acryic based sealants used to be used mostly for vertical

applications

Quote
only, if they are immersed long term they turn to mush. On a flat

roof

Quote
in winter, depending on rainfall and wind direction they could be

wet

Quote
for extended periods.

I would recommend a low modulus polyurethane sealant, and a slope > grade, (not a flow type) would be easier to use. A caulking and

sealant

Quote
supply company would be a good source.

Good manufacturers used to be Sika corp. Mameco and Tremco. Home

depot

Quote
carries Mameco Vulkem 116 last time I checked, which would be good

for

Quote
anywhere that has low movement, such as around roof penetrations.

I am going back to the SF Bay area this week and visiting with

friends

Quote
that are still in the sealant business, so I will update this next

week

Re: Update on Roof sealants

Reply #3 –
Yahoo Message Number: 26775
When you use this 3M sealant you had better not want to take the item apart again. If you let it cure for 48 hours the item is together forever. I forgot and in my prior post I think I said GE silicone, and I was corrected, the 3M product is the one to use.

Re: Update on Roof sealants

Reply #4 –
Yahoo Message Number: 26777
Can you smooth the edges with a soapy finger like SikaFlex 521 etc?

Tom Fisher
BigD

Re: Update on Roof sealants

Reply #5 –
Yahoo Message Number: 26780
Correct! I have used the3M 5200 on boats and once it sets up, there is almost no separating parts or it from the parts. See the comment in this good link on sealants http://www.westmarine.com/webapp/wcs/stores/servlet/westadvisor/10001/-1/10001/selectsealents.htm
I have used the 3M 4200 product in the past and it works as good as the 5200 AND you can remove the stuff if need be. Both sealants are widely available at marine stores and even some Wal Mart stores carry it in their marine section.

Sam

Tribute #81002

Re: Update on Roof sealants

Reply #6 –
Yahoo Message Number: 26782
To clear up a misconception from previous posts... I checked the Dicor 501 tube and it IS recommended for fiberglass roofs, as well as EPDM rubber, metal, and many other surfaces.

Bob Kumza

Re: Update on Roof sealants

Reply #7 –
Yahoo Message Number: 26790
Tom,

You can use soap to smooth the top surface, but after tooling it with a small spatular you should not need to. The Idea of the tape is to get a nice edge, and the long working life gives you time to get it looking right before you pull the tape.

Sika makes several very good Polyurethane sealants under the Sikaflex banner, 15LM is a general purpose construction sealant with good movement properties, 1A is a harder tougher version like the 3M 5200 but without the long work life.

The harder setting sealants are very good for installing solar panels and satellite dishes etc. without drilling holes in the roof, by bonding them to the roof. That is for solid fiberglass roofs only, you would not want to bond solar panels to the surface of a rubber roof in case it pulled the material loose.

Chris Bradley
Affinity 4952

Quote from: Tom Fisher
Can you smooth the edges with a soapy finger
like SikaFlex 521 etc?
Tom Fisher
BigD

Re: Update on Roof sealants

Reply #8 –
Yahoo Message Number: 26791
Allot of the good sealant is expensive so if it hasn't been mentioned I am going to mention it now for those that are tempted. Silicone seal last a long time and is cheap. The draw back with silcone though is the surface of your coach must be cleaned very good with solvent or it won't properly adhere. Another think to consider is if you have trouble getting silicone to adhere you will have a tuff time getting anything else to stick should you decide to change.
Also if you want to paint your coach latter you will probably end up with fish eyes where there is silicone residue. The residue can not be remove with solvent. Think before using silicone!

Doug Rose
4090

Quote from: Tom Fisher

Re: Update on Roof sealants

Reply #9 –
Yahoo Message Number: 26815
Boy, I agree with you on use of 3M 5200. One time in the removal of an inspection seal ring the fiberglass came along with the glue. That 5200 is some serious hold and is most often used in the marine applications. If you put something down with it... you had best not want to get it apart after it cures.
AL

00 affinity #5851

Re: Update on Roof sealants

Reply #10 –
Yahoo Message Number: 26820
It will come off your finger, but it takes a effort. Better wear rubber throw away gloves, I have been able to make a nice bead, and smooth edges. In 8 hours it is still soft. It take 24 to somewhat hard and another 24 to your done forever. I use it where water may come in contact with the glue, or I want a hard plug. It is not fast setting, that is the real issue of using this product. I repaired my office chair waited the 48 hours plus some and the chair is good today.
+
 

Re: Update on Roof sealants

Reply #11 –
Yahoo Message Number: 26832
Very good advice, especially related to painting. There is a time and a place for all these products, so it is very hard to make hard and fast rules. If paint is going to be used you are absolutely right on. It has been my experience that very few products stick to silicone. (That is why it is so great in lubrication.)