Caulking, Life-Calk or HD DAP Dynaflex 3.0

[bluewhale]

I'm rebedding aluminum windows and deck hardware on my 1976 Iroquois 30.
These two products seem very similar, but the DAP is considerably less expesive. Has anyone had any experience with non-marine caulking?

[luckytexan]

I can't address DAP, however I can tell you that for windows and deck hardware you really want something you can rely on. For that reason I use 3M products, 5200 for a perm. solution and 4200 if I think it may have to come off. Never had a leak or a problem. Can't say the same to home depot bathtub products. I have battery switches that are at the 5 year mark and the caulk sealing them to the fiberglass is just now showing some crazing on the surface but not anything that will result in a leak or anything.

I think that with windows you really want to seal them up right, as they can sometimes be difficult to get sealed properly for one reason or another, Bows, bends, flexing, heat warp, whatever. Not familiar with your particular boat but thats just my opinion. Silicone products and DAP especially do not hold up well with any of my boats needs, between salt water, flexing, sun UV issues, nothing I have tried has held up for more than a season or two when going that route. Going to west marine is a pain for me 38 miles one way, but now I make the drive to get it done one time the right way.
Hope that helps, I know I didn't answer your question directly but it always comes back to not having time or money to do it right once, but the money and time to do it over and over again.

[artbyjody]

Originally Posted by bluewhale

I'm rebedding aluminum windows and deck hardware on my 1976 Iroquois 30.
These two products seem very similar, but the DAP is considerably less expesive. Has anyone had any experience with non-marine caulking?

Do not use non-marine caulking period - you'll end up disappointed and will introduce problems such a deck rot etc if you do. The money you save now and the damage you cause to your boat in relatively short time, will then feel as if you have a student loan you can never pay off as a result of the damage water ingression will do...

see this thread

[Maine Sail]

If the frames are aluminum then 3M 101 is the best choice if they are plastic I would not advise the use anything containing polysulfide as it may not be compatible...

NOTHING on a boat is permanent so please, please, please DO NOT listen to the 5200 support group! 5200 is EVIL stuff and is nearly DOUBLE the strength, PSI peel strength wise, than the fiberglass your boat was laminated and built with!! 5200 is 100% NOT necessary!!!

Window's will eventually leak again no matter what you do! I personally do not like Life Seal due to the addition of Silicone. 3M 101 is a pure polysulfide with no silicone... You want to use a "light" adhesive and 3M 101 is 139 PSI vs. the 700 PSI of 5200..

There are plenty of threads on this subject....

P.S. I think you meant DAP Kwik Seal 3.0 as they don't make a Dynaflex 3.0 according to their web site. Neither of these products contains any polysulfide like Life Caulk does so I can;t grasp how you came away with the assumption they were similar. Life Caulk and Kwik Seal 3.0 or Dynaflex are about as similar as Rosie O'Donnel and Lance Armstrong!

Kwik Seal 3.0 also states, right in it's literature, "Not recommended for continuous underwater use". 3M 101 CAN be used for continuous underwater use as can most Marine rated sealants..
DAP also gives NO peel strength information, or strength ratings, and only calls it an "advanced polymer" but the MSDS makes no mention of polysulfide. Also absent is any exposure to UV information..

If it's Dynaflex you were talking about STAY AWAY! Latex is water based and if you seal a window frame what's inside may not dry for a long time, then, when it rains, it will leak!!


There are many things on a boat that you can save money on by buying non-marine but marine sealants are not one of them! Sure you could try and find some Thiokol, the inventor of polysulfide, but the last time I did it was the same price as 3M 101 and much harder to get...

Don't be penny wise and pound foolish. In terms of potential future repair costs, created by using an inferior product or the wrong product, the price difference between a marine sealant and DAP is .000000001% important...

[sailingdog]

I'd have to agree with Halekai. The cost difference that you save with going with the less expensive DAP product may end up being very little compared to the costs incurred if the seam leaks. Repairs are always much more expensive than doing the job right the first time IMHO.