roof caulk

[Jerry Carr]

I have a small project, I need to remove my old Girard Anemometer to replace it with a new unit.

I will need to remove the old sealant and install the new Anemometer how to prep the area once I cut away the old sealant, can I use a Lacquer  thinner?  When selecting a new sealant what is recommended?
  

[Tom and Pam Brown]

Jerry, Use the Dicor self leveling sealant.  You can use mineral spirits on the removal.

Don't know about lacquer thinner.

[Gerald Farris]

Jerry,
If you already have the lacquer thinner, you can wipe the surface before installation with it, but it is not necessary. The old sealer can be removed with a good gasket scrapper. After scrapping the old sealer off, mount the new anemometer and apply new sealer.

Gerald      

[Jerry Carr]

Thanks Gerald and Tom, I see Camping world has Dicor self leveling sealant for 4.60 a tube that will work for me. I will get the putty knife working on the old sealant and then give it a good wipe with the Laq. thinner. It sounds like a EZ job I like the EZ stuff best! Hope to see you all at Seven Feathers!

[Steve Huber Co-Admin]

Jerry,
A plastic putty knife may be better as a metal one can damage the fiber glass roof if you get too enthusiastic. Also, heating the old sealant with a heat gun will make it easier to remove.
Steve

[Dennis Crawford]

Jerry,

I did this kind of work after I retired.  First remove the old sealant being careful not to gouge the fiberglass.  The screws that hold the device are probably square head. After removing device,don't let the wires get lost. Remove any leftover sealant. Mineral spirits will assist in cleaning.  Put butyl chalk on the bottom of the new device and reattach with new screws. Tighten until you see the butyl chalk sqeeze out. Clean the butyl residu.  Then seal with a good self leveling chalk intended for fiberglass. Don't let the chalk get on the shaft.  Be careful working with device to ensure you don't break it.

Dennis

[Jerry Carr]

thanks for the heads up, I plan to change out the wind sensor nest week

[Edward Buker]

Jerry,

One of the tools that is very helpful to me in doing these jobs is a chiseled angle scraper. The handle has a metal end on it so that you can use some moderate hammer blows to work the scraper under the Dicor or whatever sealant was used. These sealants can be quite difficult to remove at times. The angle of these scrapers keeps you from damaging the fiberglass and the chisel tip is made to lift the sealant. This is an example....

 http://www.jegs.com/i/JEGS/555/80602/10002/-1?CAWELAID=1710549350&catargetid=1784155608&cadevice=c&&cagpspn=pla&gclid=CImqqrXZ77gCFQxyQgodPzkAAA

As far as Lacquer Thinner is concerned you can use it but it can soften gelcoat so use it sparingly. Sometimes because it evaporates so quickly you may not get enough work time if you are trying to remove small amounts of residual sealant but it will effectively clean the surface quite well . Mineral spirits will give you better work time. You may not get the surface so that every last remnant of prior sealer is removed and that is O.K.  After removing all you can and you have used solvent to clean the surface you can lap the new sealant over any small amount of residual sealant as well as the fiber glass and anemometer base. I also like Dicor lap sealant.

You are likely to find wires that do not match for color coding between the old and new anemometer. It uses a magnetic field to open and close a reed switch. It is used as a pulse generator so either wire can be connect to either wire coming from the coach....there is no polarity.

Later Ed

[John Harris]

As stated earlier by someone, make sure you have a hold of the wires when you clip them off from the old unit as they will fall back inside the coach and can be a little difficult to retrieve. I have made that mistake! Once....

[Jerry Carr]

Thanks everyone for your help, I plan to tackle the project next week and will take some photos to report my progress

[Keith Oliver]

I found Toluene worked very well to clean the existing sealant, so I would recommend using it to clean the surfaces prior to re-sealing.  Longer working time than lacquer thinner, way better at cleaning the sealant than mineral spirits.

[Jerry Carr]

Thanks Keith, I will give the toluene a try later this week I did find a plastic scrapper and will hope to cut off most of  the sealant  before the clean up

[Edward Buker]

Jerry,

I have spent my fair share of time on RV roofs working to remove old sealant around installed items and I have found the leveling sealants to have a very strong surface bond and the material itself to be quite a challenge to remove. Unless I have missed something I cannot envision a plastic putty knife being up to the challenge but maybe you will have better results than I did.

Later Ed

[Steve Huber Co-Admin]

Ed,
It will if you heat the sealant with a heat gun. Cold, no way.
Steve