Water proofing the hull.

[arrowskartax9]

Hi Guys, I have a MHZ Mystic m and i am having a hard time keeping the water out.
Its coming in from the rear of the boat and i am filling the bath to submerge it to find the leak. My question is, What is the best way to seal the inside of the hull including where the screws come through the rear of the boat that hold the rudder and the arneson surface drives.
Chris.

[m4a1usr]

Water entry can be a mystery from many aspects. The obvious is from the drive lines. Seems to be the most common. From the hardware mounting screws would probably be the second most obvious. But another to consider is as plain and simple as the water tubing. The ends have to be crimped or sealed with zip ties and then there is the cooling jacket seals. All are contributors or potential leak areas. Finding which one is the cause will test your abilities.

I always seal the indside of my hulls with thinned out Shoe Goo. Has never let me down. But on the outside I like to use silicone then mounting fins, brackets and stingers.

John

[arrowskartax9]

Thanks John. I have done a float test in the bath and the water is coming in from 2 spots.
1, Is the screws that bolt the surface drive through to the rear of the hull on 1 side only.
2, Is the other surface drive where it bolts up to the underneath of the hull to adjust the drive angle.
Any ideas on what to seal it with that will create a water tight seal?
Chris.

[sailr]

I recently had a problem with my DF 33. I mixed up a good sized batch of 30 minute epoxy and poured it in around all the bolts on the inside while holding the boat vertical with the bow up. Cured my problem completely. You can try using silicone but I've never had great luck with it.

[arrowskartax9]

Thanks for your info, But what happens if you need to unbolt the hardware from the boat and the screws have 30 minute epoxy all over them.
Sorry, i dont mean to be a smart xxxx but can the epoxy be pulled of in case something has to be replaced.
Chris.

[siberianhusky]

I take the hardware off and seal it from the outside with latex caulking, like Mono etc.
When you bolt the hardware back on the excess squeezes out and can be wiped off with water.
It is paintable as well and doesn't mess up the hull for future paint. Thats why I don't like silicone on the outside, will always cause issues for paint. You can never seem to get it all removed.

[NativePaul]

If using silicone the screws will just rip through the silicone when you want to remove them, and I guess latex would be the same, if using Epoxy on the inside smear some Vaseline onto the screws before doing them up then apply the epoxy over the screw/nut/washer, not only does the vaseline stop the epoxy sticking to the screw but its stuck the nuts to the hull effectively turning them from locknuts into blindnuts making it easier to take the hardware on and off in future, I like to use silicone under the hardware and epoxy thickened with micro-balloons over the nuts.

[arrowskartax9]

Great, thanks for all of your help, i will take it off and reseal it.
Regards,
Chris.

[dana]

Yeah just use plumbers putty. Silicone will make painting In the future a pita

[arrowskartax9]

What brand of plumbers putty?

[dana]

i dunno sta-put will work

[arrowskartax9]

Ok thanks.

[jamespl]

in the past i have wrapped a bit of PTFE tape around the screws on the hardware and that seemed to work ok.

[tanasit]

I just recoated my roof with the white polimer, so I tried that and it works great. If you can reach the area, just brush on otherwise I did just like sailr by pouring the mixture while having the boat sit with the bow up. Also on my Pursuit, I needed to replace the strut to the adjustable one and the white polimer can be peeled off and recoat as needed. You can use a hobby knife to score around the area to remove so that you won't peel off the rest.
Down side: a gallon will set you back $29.95 at Home De??? But good to keep for unexpected repair leaky roof too.
They have 2 kinds, one with 7 year warranty and the other that I used is 12 yrs.
Note the surface must be clean and dry and DO NOT add water because it won't cure.

[sundog]

I remove the leaky hardware and use silicone caulking. When reinstalling, I just snug up the screws finger tight, and remove excess caulking before it cures. The next day, I tighten the screws down. Works every time.