thompsondockside.com

I am refastening my 1960 Seacoaster below the waterline which involves (among other things) removing the machine screws, prying the laps (or is it the strakes?) apart, applying 3M 5200, then putting in new machine screws. My works space is unheated although I have a propane space heater to take the edge off when I'm working. Living in New Hampshire it gets a bit cool this time of year and I am concerned that the 5200 won't cure properly. I can apply the 5200 above the recommended 40 degree but once the propane heater is shut off it cools down pretty quickly and stays cold until I fire the heater back up.
I really want to be able to get this part of the job done over the next month or two but don't want to mess things up. Does anyone have any thoughts?

Thanks for your help.
Paul

What do the instructions for the material tell you? I am betting the 3M5200 must have a minimum temperature. That means not just the air around the boat but the wood of the boat itself and for the alloted time period the material needs for curing.

If the container does not tell you, give 3M a call.

Andreas

Thanks for answering. The info on the tube states that 40 degrees is the lowest recommended temperature for application. I can get the air and the boat material above that with my heater but I can not maintain that temp for the time the 5200 needs to cure.

I also need to re-seal the planks below the waterline in my Seacoaster so I did a search on that product right after reading your post. A lot of people advise staying away from that product unless you want the repair to be Permanent! Some recommend Sika-flex instead and also advise to stay away from a silicone product at all costs.

Verne

I want it to be permenent. This boat will not take another refit so I want to make sure it is solid, safe and water tight. After looking at all the posts here, and else where and reading the book by Danenberg, 5200 seemed the best way to go.

The 3M 5200 is $25.00 per 10oz tube. The Sikaflex 221 is $6.25 per 10oz tube. How many tubes will it take to do your lapstrake? Try a Google on the Sikaflex product. Compare the specs on tensile strength, tear resistance, shear resistance, movement, elongation and shrink. Sikaflex can also be sanded and painted.
Just trying to help........... (I have no connection to either company)

Verne

I had the very same question and called the 877 number on the tube for Marine Technical Support. I was told that there would be no problem if the work area dropped in temperature below the recommended application temperature. In fact, the temp can drop below freezing. The curing process will take longer as it does not cure in extreme cold. However, the curing process picks up again with warmer temps. The main caution is that the 5200 MUST cure before you can paint over it. How do you know it is cured? If you push on it, it should feel like firm rubber. If it is "squishy", it's not yet cured. Hope this helps.

Oh yeah...my local True Value Hardware sells 3M 5200 for 14.95 a tube. One tube did my keel and sealed all the lap joints on my 14' Cruisers Inc. Holiday.

That's good to know. I can get the temp of the boat up by placing some incandescent light under the upturned hull. I figure if I keep them burning when I'm not using the heater I can at least keep the hull wood at around 40 degrees. I'm not sure how much of the 5200 I'll need to buy but the container indicates a small bead, which is what I'll require should get me between 30 and 100 linear feet.
For what it is worth, Jamestown Distributors has the 10 oz tube of 3M 5200 for 12.99, plus shipping.

Paul

I'm glad you found the product you wanted for a reasonable price. Good luck with the repair. Happy leak-free boating!
Verne