Caulking Windshield

RS340DA

RS340DA

Member
Aug 19, 2018
37
Michigan
Boat Info
2004 Sea Ray 340 Sundancer (SDA)
Generator
Raymarine Electronics
Bow & Stern Thrusters
Engines
8.1’s with V Drives
Looking for some advice from those who have dealt with recaulking their windshield.
I am struggling to get the old caulk out from around the exterior of my windshield on my 04’ 340. I was able to get some out, but certainly not all of it. Will the new caulk bond to the old caulk? I was planning to clean the area with Acetone/water mix and use 3M 4000 UV or Boatlife Lifeseal (white). Also, I read another thread that said to put down vinyl or painters tape on the deck and windshield trim to give crisp lines and reduce the cleanup/mess. I assume the tape is supposed to be removed immediately after caulking so it doesn’t bond to the tape, correct?
 
I haven’t done a windshield, but have done rub rails and other. Life Seal is good stuff. Does not yellow and is a great product. Unless you are a “pro level caulker,” I would suggest painter’s tape above and below your caulk line. Removing the painter’s tape 15-30 minutes after applying caulk worked well for me. Also, a small cup of alcohol to dip your finger in if you are smoothing also worked very well.

I have also removed what existing caulk I could, cleaned with alcohol or acetone, and never had an issue with the new bonding with the old.

You will not go wrong with the Life Seal products!

Bennett
 
I have re-caulked the windshields on both my 320 & 420DAs and in both I removed all the old caulk and cleaned the surface with straight acetone. Some of the old caulk was slimy and gross so remember, new caulk is only as good as what it is adhered to.
I used the blue painters tape and did one section at a time and removed tape right away, good idea, like mentioned before to have a small cup of actetone and wet your finger and go over bead while caulk is still wet.
 
All excellent ideas/tips. While you’re at it, you should remove the screw cover molding in the windshield where it rests on the deck. Remove the screws, one at a time, and put some BoatLife caulk in the hole and put the screw back in. I had a leak from the screw holes years ago.
 
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I wouldn't use the 3M 4000 products for caulking; these are adhesives and for structural bonding. You will never get a good surface finish nor acceptable weathering. New boat manufacturing has pretty much gone to Sika products for sealing, caulking and adhesives. Sikaflex 295UV would be the appropriate caulking/sealant for windows. There are silicone sealants, polyurethane sealants, and polysulfide sealants, then there are the hybrids like polyurethane/silicone; each has their place and purpose. My boat is being done professionally and they are using a commercial Sika product which is essentially 295UV packaged for bulk use. I am very happy with the outcome.
 
If your application can use a mechanical method for removing the caulk considering using a oscillating multi-tool. I bought a cordless one and it quickly became the most versatile tool in my (fairly large) toolkit.

There are a couple types of caulk-removing blades available. Two wide, flat scrapers (one flexible, one rigid), and a longer caulk remover blade. They worked extremely well for removing caulk from a variety of spots on my boat.
 
ttmott said:
I wouldn't use the 3M 4000 products for caulking; these are adhesives and for structural bonding. You will never get a good surface finish nor acceptable weathering. New boat manufacturing has pretty much gone to Sika products for sealing, caulking and adhesives. Sikaflex 295UV would be the appropriate caulking/sealant for windows. There are silicone sealants, polyurethane sealants, and polysulfide sealants, then there are the hybrids like polyurethane/silicone; each has their place and purpose. My boat is being done professionally and they are using a commercial Sika product which is essentially 295UV packaged for bulk use. I am very happy with the outcome.
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I second Sika. I redid my caulk all around the windshield using it. I also used blue painters tape. That was 3 years ago and still very happy with the result
 
Correct me if I'm wrong but I believe 3M 4200 is for non-structural and 5200 is for structural bonding. I was just researching it yesterday to reseal a portlight.
 
kkirby7226 said:
Correct me if I'm wrong but I believe 3M 4200 is for non-structural and 5200 is for structural bonding. I was just researching it yesterday to reseal a portlight.
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They are both for structural bonding. 5200 is permanent and 4200 is removeable.
 
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