Caulk removal from Rubber Roof ?

[Howard R]

Hi all,

I've been lurking for a while and learning a lot ... lots of knowledge and great folks from what I see!  Thanks everyone!

Now I have a project and questions ... I know someone out there has words of wisdom to impart    ... recently cleaned the rubber roof on our (relatively new to us) 1999 Coachmen Mirada and it's time to do some maintenance.  The caulk is developing cracks, as far as I know I don't have any leaks yet, but don't want any either.

How difficult and what tools are needed to remove the old caulk (Dicor I presume), without damamging the rubber.  Looks like caulk was added at one time or another, for example the strip that covers the joint between the rubber and the end caps is about an inch wide.  Instead of running a bead of sealant along the edges the whole strip is covered as well as the edges.  I have some phenelic (sp) (wood like) scrapers that might be better than a putty knive, but open to suggestions.

Would appreciate any suggestions if you have tackled this job before. 

thanks,

Howard

1999 Coachmen Mirada 28Q
Denver, Colorado

 

[Karl]

Howard,

I've found that my trusty old veneer knife works wonders. It's got teeth, so it's actually more like a saw than a knife. The handle stands off from the blade so you can lay it flat along the roof surface, and the teeth don't have an offset, so you won't damage the underlying surface. The teeth on one side are set to allow pulling the knife along the surface; the teeth on the other side are set for pushing the knife. You can find one at any woodworker's shop for less than $10, and they're worth every penney. 

 

[Gary RV_Wizard]

An alternative is to cover the entire existing seam with Eternabond roof sealing tape, which is about 4 inches wide and sticks like crazy. You should never have to caulk tht seam again.  Eternabond is available in white or aluminum finish.  It's pricey, but a heck of a product.

Annual maintenance is recommended on caulked seams, but the Eternabond is essentially "forever", as its name suggests.

 

[Ron]

I will second RV Romer's recomendation for Eternabond,  excellent product and is available from Camping World.

 

[Howard R]

... trusty old veneer knive works wonders

Karl, I like that idea!  I'll have to check that out tomorrow.

... cover the entire existing seam with Ethernabond roof sealing tape ...

Gary and Ron, thanks for that info.  How well would it work around the various vents, etc?  Would you have to remove the current sealant first?  Understand it would be essentailly a permanent fix, but wonder if it would seal well around the vents over the sealant.  I'll have to go take another look at the seals up there.  But I like the long term potential!

thanks,

Howard

1999 Coachmen Mirada 28Q
Denver, Colorado

 

[Ron]

... trusty old veneer knive works wonders

Karl, I like that idea!? I'll have to check that out tomorrow.

... cover the entire existing seam with Ethernabond roof sealing tape ...

Gary and Ron, thanks for that info.? How well would it work around the various vents, etc?? Would you have to remove the current sealant first?? Understand it would be essentailly a permanent fix, but wonder if it would seal well around the vents over the sealant.? I'll have to go take another look at the seals up there.? But I like the long term potential! thanks,  Howard  1999 Coachmen Mirada 28Q  Denver, Colorado 

Follow thr instructions that comes with it.  The main thing is to make sure you clean the surface with alcohol.  Conditions of the existing sealant determines whether or not you can apply Eternbond over it.

 

[Howard R]

Follow thr instructions that comes with it.  The main thing is to make sure you clean the surface with alcohol.  Conditions of the existing sealant determines whether or not you can apply Eternbond over it.

Thanks Ron, I'll have to take a look at Eternbond next trip to Camping World.

Howard

 

[Gary RV_Wizard]

You can get the White Eternabond Roof seal  at http://bestmaterials.com/Eternabond.aspx.  4"x50 foot roll is $41.99.

Another good source is Big Rocks Supply, http://www.bigrocksupply.com/cgi-bin/webc.cgi/st_prod.html?p_prodid=1447&p_catid=395. They also carry the 2" width for only $24.

This is the same as the shorter rolls of "RV Roof Seal" product sold at CW and other Rv stores.

 

[holemania]

hello everyone....i'm a newbie here, but i'll jump right in as i'm in a critical situation with my rv roof. 

we just elevated from "tenting" to a 1990 37' pace arrow....big jump! 

well, we just went thru a gulley washer of a rain and it's very obvious that we have a few leaks in our rubber roof.  i've inspected the roof and there's old silicone/rtv in all the roof seams that is cracking, etc.  so, i know it's only a matter of time before i get numerous leaks sprouting everywhere. 

i've read the posts here re: eternabond and just purchased the product.  well, i spent a couple of hours today trying to get the old silicone off, but it seems to be an endless job....sigh....

so, my question is:  do i have to get every speck of the old silicone off?  even if there's some old residual dry silicone in the pattern ridges of the rubber will the eternabond seal nicely?

if the silicone was spread on wider than the 4'' width of the tape can i tape one length on one side of the seam and overlap the first length with another length?  effectively getting a 6-7" width with a 1-2" overlap? 

will this stuff adhere to itself with good watertight integrity  if i overlap it? 

any other feedback on products such as acetone, etc. or tools to use to clean up this old silicone sealant would be quite helpful. 

also, if water has already gotten to the wood between the interior and exterior walls am i in danger of rotting or continued rotting even if i repair these leaks effectively now?  i've already got some "bubbling" or delamination in some areas....

thanks for any feedback you guys might offer and thanks for all the tips i've already gleaned!

dave

 

[holemania]

hi all,

one other "dumb" question....

now that i've read closer about how to apply eternabond, i see that it says not to appy to silicone....does this mean any and all caulking on the roof seams?  most of the seams on my roof have the hard, dry caulking....i'm not sure that this is silicone based.  wouldn't the silicone base stuff be more rubbery?  how can i know for sure?

thanks!

dave

 

[John From Detroit]

I don't think I have ever seen silicon get "Hard and Dry" so the answer to your question is yes, it's likely NOT silicion

Other forms of caulk do,however, get very hard after a number of years of rain and sun

 

[Gary RV_Wizard]

Yes, you can overlap eternabond.  I had a large tree limb fall through the roof of a metal storage shed and I fixed the large hole by merely overlapping strips of Eternabond. It has held well for 5 years now!

The hard & dry caulk is not likely to be silicone. Go ahead and try the Eternabond in one area and see if it sticks. If you still can't pull it off several days later, it has probably bonded OK. 

Make sure the Eternabond completely covers the old caulked area so that the edges bond to the roof and not the caulk.  That way, any leaks in the caulk are covered over with the Eternabond.

You can use mineral spirits SPARINGLY to clean around the area where you will apply the Eternabond. I say "sparingly" because it can penetrate the rubber and loosen the glue that bonds the rubber to the roof.  Dampen a rag with the mineral spirits and wipe the area clean, then use a dry rag to wipe up any residue or the solvent.  Maybe even wash the area clean with detergent and water after using mineral spirits.  Let it dry thoroughly before applying the Eternabond.  I would be very hesitant to use acetone because it penetrates the pores of rubber very quickly and disolves most anything, possibly including the rubber itself. 

 

[holemania]

thanks for all replies...

actually, i mis-spoke....i don't have a rubber roof......it's a domed hard plastic shell roof (not sure of technical name), so I may be ok using acetone sparingly to clean up old caulk residue before applying eternabond.

dave

 

[holemania]

i'm pretty sure it's a domed fiberglass roof now...

well, i sealed all the seams on the roof this weekend.....double-seamed overlap with the eternabond in many places...

it adhered very well....

then, i laid one coat of "white" uv protectant....

went camping for the evening still with the blue masking tape outlining my painted areas....ha ha!

came back today and got the 2nd half gallon of the uv protectant tinted to match my rv color....and laid the 2nd coat...

it looks like it's sealed very well......i'll just have to wait for the next rain to know for sure!

thanks again for all the recommendations for eternabond!

now, to get the dometic rm2804 frig working....gets barely cool in the freezer on electric and propane,  but will not get down to proper temps.....aaarghhh!

dave

 

[rhmahoney]

A few suggestions that may help your fridge cool better.

Defrost the freezer.
Put a small muffin fan atop the chimney, sucking air upward.
Shade that side of the RV.
Move rig to Greenland.