Need to wait full 7 days for 5200 to cure?

JASinIL2006 · Jun 20, 2012

Hi all, I am adding a transom-mounted transducer to my fiberglass boat. I created a mounting block out of poly board for this and future transducer mountings. I drilled two holes into my hull, filled them with 3M 5200 adhesive (not the quick curing variety) and then I back-buttered the poly board with 5200, packed the thru-holes in the poly board with 5200, and screwed the thing onto the transom (see below).

I got a good amount of 5200 oozing out around the edges and from the screw holes, so I think I pretty thoroughly sealed that sucker to the boat. My question: how long do I need to wait to use the boat? The directions say 5200 fully cures in 7 days, but it also says it cures underwater. Can I use my boat this Sunday (the block was mounted Tuesday evening) or should I wait at least seven days? I'd like to go boating this weekend, but I obviously don't want any chance of water getting in those holes.

Thanks,
Jim

spoilsofwar · Jun 21, 2012

Re: Need to wait full 7 days for 5200 to cure?

You are good to go... it will finish curing in the water if it hasn't already. Next time use fast cure for peace of mind if its the sort of thing that tends to bother you.

Texasmark · Jun 21, 2012

Re: Need to wait full 7 days for 5200 to cure?

I never used 5200 but it gets mentioned on here frequently. If it is made of silicon and is a Room Temperature Vulcanizing (RTV) compound, once it skins over it's through with the outside world. Only thing would be if you put a lot of pressure on it before it's at least moderately cured. In your application, I wouldn't cause the environment to be classified as excessive pressure. Like you can have a tube of RTV that you got into once or twice, allowing air to come in contact with the contents, screw the lid on and 6 months later come back to use it again and the tube is hard....fully cured, no additional exposure to air. As far as water, some versions cure quicker in high humidity (water exposure) conditions. Nuf said.

Mark

Mark

Fireman431 · Jun 21, 2012

Re: Need to wait full 7 days for 5200 to cure?

Once it skims over (12-24 hours), it's water tight. After 7 days it can have "excessive pressure" exerted on it. Applied it Wednesday? Boating Sunday? Absolutely. I put in two 1 1/2" holes in my transom for lights and had it back in the water the following day. Sealed perfectly.

Georgesalmon · Jun 21, 2012

Re: Need to wait full 7 days for 5200 to cure?

5200 is a polyurethane. not a silicone. Yes, go boating. Today if you want to.

Bob_VT · Jun 21, 2012

Re: Need to wait full 7 days for 5200 to cure?

Uhhhhhhhh you might have a problem....... the 5200 really will not stick to a poly piece and you will be able to peel it away once it is dried.

Normally 5200 will even cure under water and you can boat within a day of application.

Keep an eye on your work when cured.

ricohman · Jun 21, 2012

Re: Need to wait full 7 days for 5200 to cure?

I agree with the above post. I went with an mount that epoxys to the hull with no screws. The board you are using will need screws to hold it.

JASinIL2006 · Jun 21, 2012

Re: Need to wait full 7 days for 5200 to cure?

Thanks, all. I guess I won't worry about it.

Bob_VT, the poly piece is really held tightly to the transom by the screws; the 5200 is essentially sandwiched in between and I was thinking it would simply provide a bit more barrier to help prevent the water from reaching the screw holes in the transom. If I didn't have the poly board and I had instead just sealed screws using 5200, I'd be OK, yes? The sealant applied on the back of the poly board was just extra insurance. Also, I didn't want water-borne crud getting under the poly board and allowing algae or anything ugly to grow.

Thanks all!

Georgesalmon · Jun 21, 2012

Re: Need to wait full 7 days for 5200 to cure?

I put a piece of starboard on my transom to mount stuff with out adding any more holes in the boat when I change something. Just the three to mount the board. Well, dummy(me) screwed up and had the board mounted to low. So I removed it to cut shorter. I know 5200 won't stick to poly but somebody needs to tell the hammer and three crow bars I had to use to get it off.

ezmobee · Jun 21, 2012