One of my tasks to complete this summer is to remove and replace the caulk that seals the trim pieces along the length of the coach.
Is there a "best" caulk for this application? Budget constraints are a consideration, but I will spend what is necessary if warranted.
Thanks in advance.
I would probably use the 3m 4200, here is a chart.
https://www.jamestowndistributors.com/userportal/document.do?docId=510
John
Steve, I use M1 made by Chemtech, excellant adhesion.
johnH
M1, Sikaflex, and 3M 4000 are caulks that are often recommended by more seasoned RV folks. These adhere, and last a long time. Stay away from silicone caulks like GE, DAP, etc.
3M 4000 was the only one readily available in our area, so that's what we went with. The motorhome has been through some very serious storms and we've been very pleased with the results. Wore nitrile gloves, dipped them in a bit of water and smoothed the final seam. Nice results.
I can't speak for the M1 or Sikaflex, but the 4000 does not attract dirt and dust like other caulks.
If you plan to do something like replace marker lights, then another option is to purchase a good quality butyl tape and use that to bed the fixtures and screws. There are different grades of butyl tape.
Chris
Steve, use the 3M 4000 UV variant. It will last longer in sun exposed locations.
Available at Amazon. Shop around, you might be able to find a lower price.
Amazon.com: 3M 06580 Marine Adhesive/Sealant Fast Cure 4000 UV, White / 1/10... (https://amazon.com/3M-Marine-Adhesive-Sealant-Gallon/dp/B000XBDJWC/ref=sr_1_1?rps=1&ie=UTF8&qid=1491958783&sr=8-1&keywords=3m%2B4000%2BUV&refinements=p_85%3A2470955011&th=1)
Follow up questions.
What is recommended to clean up the recommended caulks? Water? or Acetone?
How many tubes, to do both sides? I know it depends, but is it a 2 tube job or five?
TIA
Here is the Data Sheet for 3M 4000 UV.
Cleanup with acetone or toluene (no nearby ignition source). Do the cleanup before it cures. Acetone or toluene may take off paint on the trim parts. Paint thinner might work for cleanup and won't usually take off the trim paint. Test to be sure.
Probably figure two 10 oz tubes each side. I am doing front and rear cap strips this summer and am planning on two for each end. If you have a part of on unused tube wrap the end of the nozzle with an airtight tape like packaging tape. It does a pretty good job of keeping it useful for quite awhile. I always have a 3oz tube on hand for jobs on the road.
Roger,
Thanks for mentioning 3M 4000's UV properties. I made a mistake in my earlier post. We used the 4000, and not the 4200 (I checked our supply), because of the UV rating. 3M 4000 still has very good holding power for bedding items.
Our U-320 is gelcoat. Prior to application we cleaned the areas with denatured alcohol to remove residues, etc. I also had acetone on hand for areas where silicone caulk had been used before.
We used two tubes. Did the front cap band, five marker front marker lights, GPS and satellite radio patch antennas, and portions of the rear cap top band and side bands.
Chris
I just resealed my roof and used MasterSeal NP1 by BASF at the recommendation of a contractor friend. I had water intrusion around the front interior light fixture and signs of moisture were showing on the roof carpet. I am not sure if anyone else has had experience with this product, but for now it seems to work well for now.
Originally, I went to the box stores and neither of them carried NP1. The associate in the paint department commented that NP1 was a very good product, although they did not carry it. I ended up purchasing a case from Contractor Supply in Lufkin because I didn't know if I would need one tube or a dozen. They were kind enough to tell me upfront that I could bring back any tubes that were not used for a full refund, which they honored.
It took about 2 1/2 tubes to do the roof, which included around the A/C units, luggage rack, ladder posts, shower skylight, kitchen exhaust, bathroom roof vent, TV antenna, air horns, antennas, satellite dome, and anything else I am forgetting. I kept a spare tube just in case, and was informed when I returned the portion of the case that I did not use that the shelf life is not indefinite and an unused tube is good for six months to a year. It is a white sealant and will likely discolor with U.V. exposure, but visibility of the applied areas is limited from the ground so I wasn't too concerned with discoloration on this specific project.
I believe I paid somewhere in the neighborhood of $5.50/tube. If anyone else has used this product on their coach, I would be interested to hear how well it has held up versus other comparable products. This project is already done for now but it is only a matter of time before another leak pops up.
If I was contemplating redoing the caulk on the side strips at the same time I would also remove the strips and maybe the side
panels and rust proof any metal in back of the panels.John Haygarth could add to this he is the master of panel removal.