Removing caulk from rubber roof

[wtmtnhiker]

Hi all,
Looking for some advice on removing old (2010) caulk from a rubber roof on my son's 2010 KZ Spree. I'm replacing the vent fan with a fantastic fan. I have taken all the caulk off from on top of the old metal flange but there is still a thick coating on the rubber roof. The caulk is hardly pliable anymore and stuck fast to the roof. Can I put new caulk on over the old? I do have Eternabond but will that stick to the old caulk?
Suggestions would be appreciated.

[drsteve]

The Eternabond site says to use acetone, but I've had good luck using mineral spirits on EPDM. Small amounts, and wipe it off with a rag.

[LarryJM]

wtmtnhiker wrote:
I used mineral spirits on a 5th wheel that I had and it made the rubber pucker up and wrinkle. Wouldn't denatured alcohol work just as well?

Mineral spirits is probably one of the worst cleaners for Eternabond there is IMO. You need something that evaps quickly and leaves no residue like Acetone or Lacquer Thinner.

Larry

[wtmtnhiker]

I used mineral spirits on a 5th wheel that I had and it made the rubber pucker up and wrinkle. Wouldn't denatured alcohol work just as well?

[drsteve]

wtmtnhiker wrote:

ksg5000 wrote:
If you end up tearing the rubber roof suggest you patch with Eternabond. I use a rockwell sonicrafter with special flexible caulk removal blade (http://multifitblades.com/flexible-scraper-blade-271.html).

Got lucky and did not tear the roof but there was a small tear under the old vent already. I caulked it but the tube says it does not fully cure for 30 days so I assume I should wait the 30 days before covering wit eternabond?

Let it set up for a day and cover with eternabond. The trick with eternabond is to clean where you're using it with mineral spirits first, then use a small roller to press the tape down after it is applied.

[DutchmenSport]

If the old is stuck THAT well to the rubber, why remove it at all? Just apply new on top of it.

[wtmtnhiker]

ksg5000 wrote:
If you end up tearing the rubber roof suggest you patch with Eternabond. I use a rockwell sonicrafter with special flexible caulk removal blade (http://multifitblades.com/flexible-scraper-blade-271.html).

Got lucky and did not tear the roof but there was a small tear under the old vent already. I caulked it but the tube says it does not fully cure for 30 days so I assume I should wait the 30 days before covering wit eternabond?

[ksg5000]

If you end up tearing the rubber roof suggest you patch with Eternabond. I use a rockwell sonicrafter with special flexible caulk removal blade (http://multifitblades.com/flexible-scraper-blade-271.html).

[wtmtnhiker]

Thanks everyone for the suggestions. I'll remove all the old caulk that I can without risking tearing the roof fabric, then I'll caulk it and maybe Eternabond over that once it's dry.

[tnedator]

rhagfo wrote:

tnedator wrote:

gbopp wrote:
You can use a heat gun and plastic scraper to remove the old caulk.

There is also a Caulk Remover available.

I just remove the loose caulk. Clean the remaining caulk and apply new over it.

Eternabond will stick to the old caulk. Just clean the area well before applying.

How "delicate" is the rubber roof? I'm just wondering since you recommend using a scraper.

Stated Plastic scraper used with great care.

Sorry, I did see plastic, but didn't repeat it. 🙂

Do the same instructions apply to TPO?

[rhagfo]

tnedator wrote:

gbopp wrote:
You can use a heat gun and plastic scraper to remove the old caulk.

There is also a Caulk Remover available.

I just remove the loose caulk. Clean the remaining caulk and apply new over it.

Eternabond will stick to the old caulk. Just clean the area well before applying.

How "delicate" is the rubber roof? I'm just wondering since you recommend using a scraper.

Stated Plastic scraper used with great care.

[tnedator]

gbopp wrote:
You can use a heat gun and plastic scraper to remove the old caulk.

There is also a Caulk Remover available.

I just remove the loose caulk. Clean the remaining caulk and apply new over it.

Eternabond will stick to the old caulk. Just clean the area well before applying.

How "delicate" is the rubber roof? I'm just wondering since you recommend using a scraper.

[gbopp]

You can use a heat gun and plastic scraper to remove the old caulk.

There is also a Caulk Remover available.

I just remove the loose caulk. Clean the remaining caulk and apply new over it.

Eternabond will stick to the old caulk. Just clean the area well before applying.

[ADAD437]

i use dicor self leveling caulk. if it is a rubber roof do not use regular caulk.

[eHoefler]

Use a heat gun to soften the old caulk