View Full Version : Replacing stock siliconed in thru hull tips?????

12-06-2012, 02:40 PM
I purchase a set of angle cut tips with built in flappers and silencers. Anyone that has removed the silicone-rubber installed stock tips, just looking for some advice and or what I am in for? I removed the screws and started to razor blade around them but the stuff is tough!! It seems if I start now, I might be ready for spring!!!Anyone that has been there I would appreciate it. :uzi:

12-06-2012, 03:15 PM
Sure its not 5200? I have used the 3m 5200 remover and it works really well.

12-06-2012, 03:35 PM
Quote: "Sure its not 5200? I have used the 3m 5200 remover and it works really well." I don't know what the heck it is, but it's TOUGH. Whatever Donzi used at the factory in 1995 is what it is!! ps.. I still cannot access my profile or anyone elses??

Morgan's Cloud
12-06-2012, 05:16 PM
5200 , the other invention of the devil , stealing a quote from Brownie.

Exhaust through hulls are not an appropriate application for 5200 and if they used it at the factory they need their azzes cut.

I've never used the 5200 solvent before but incase that's what the stuff is then give it a try. If it's not 5200 then maybe the patient use of something like lacquer thinner will slowly soften the stuff up.
Sounds like a tedious job ahead.

Use a polysulfide based sealer when installing the new ones. Easy to work with, now and later. Remember , you only need a bead around the two sides , NOT all the way through.
The next owner of the boat will one day love you for it . :kingme:

12-06-2012, 05:32 PM
All of the removers are messy to say the least, have ample acetone and rags ready. When you pull the tips the stuff comes out real stringy, cover anything that might get some of the mess on. It dries almost immediately an is a bioch to get off. Another product that works well is skip sand which is a bottom prep. I have used skip sand to remove the salon window on Hatteras's works extremely well.


12-06-2012, 06:14 PM
3M 5200 Adheive/Sealant is super strong stuff.
It will pull the surface gellboat, or laminate ,of the fiberglass , or wood off before it fails itself.
Never used the remover~~~but it sounds like a great idea.
You may also use a very sharp & thin putty knife with a hammer to get under the glued-on exhaust flange itself.

3M 5200 does have it's uses.
We had a plywood lapstrke 1963 Lyman 22' that always had leak issues on each side of it's white oak keel at the garboard plank seams, and along it's bow & stem areas.
We tried Boatlife Polysulfide, Dolpinite, Khuls, Seamlast, Roofing Compound etc, as well as other caulk products along with traditional hammered in caulking rope, with no long term luck sealing of these large critical seams.
The boat leaked badly after only a month or so as the boat ran at 38 MPH and actually plled the caulk out in long strips..
Once we discovered 3M 5200, and bought a case of it, our leak problem was solved Forever !.
This strong adhesive caulk lasted at least 25 seasons underwater with no failures.
We swear it heald this boat's bow together.

12-06-2012, 06:40 PM
Ghost is right it will pull the Gel and somtimes the laminate which i have seen more then once .

12-06-2012, 06:55 PM
I've never tried it, but I've heard a little heat will help you separate the 5200 and the tips with out the other stuff.

12-06-2012, 06:55 PM
Years of experience taught me to heat the small scraper, the scrapper must ave the corners rounded and softened so as not to cause any damage which is very easy to do. heating the scrapper allows it to be pushed into the hardest aged 5200 with ease. Once you establish a pocket at the "top" use an squirt oil can to fill the pock with a liquid product like Skip Sand. Give it a little while to soften the 5200, check every so often with the scrapper. The scrapper will move along slowly, don't try to rush it!


12-06-2012, 07:06 PM
After doing some research, I doubt the Donzi factory would have used a permanent adhesive for tailpipes. So there is no point investigating 5200 any further. 99% sure it is Silicone-rubber sealant such as Boatlife.

12-06-2012, 11:03 PM
Heat evenly from the inside with a propane torch. You will hear it crackle. Stop and give it a pull it should slide right out.

12-07-2012, 04:21 PM
Very thin wood wedges work well, and minimizes any damage.

Use two or three at a time.

12-07-2012, 07:28 PM
I agree, I was at my "hate the color orange" store looking for hardwood shims. They only had cedar which is way to soft. I have some delrin blocks, which I was thinking of ripping shims on my table saw they will be pretty rugged but won't mar anything. Your suggestion works for me as I was leaning in that direction myself. Also putting a 4"OD pvc fitting inside the pipe to wiggle it around, while driving in the shimes.
Thanks all.

12-07-2012, 08:00 PM
I just replaced mine. I used a thin flexible putty knife to slip in behind the flange. Kept putting in in all the way around to slice the silicone and they came out after a few mins.

Bobby D
12-13-2012, 07:32 AM
Last year I replaced my old exhaust tips with new SSM internal flapper tips. Not sure what type it was but the previous owner used a marine caulk that Chris Craft would have used back in 2000. When I removed the old tips the calk was still sticky and soft. I used and 8 ounce rubber hammer and a block of wood and hit them from behind until they stated to move. Than I grabbed the end and worked back and fourth and a few more hits with the hammer and out they came. The starboard side was by far the hardest to remove due to the amount of calk used. The gel coat is tuff stuff and held up fine.

12-13-2012, 12:26 PM
Thanks, I have also try to pic document everything I am upgrading. It helps when you try figure out how much $$$$$$ you sink into these play toys!

12-13-2012, 10:53 PM
It helps when you try figure out how much $$$$$$ you sink into these play toys!

What is this "figuring out" you speak of?

12-14-2012, 02:20 PM
The quotes don't work .... but...
I keep track of the $$$... and work... that is what I speak of.

12-15-2012, 07:23 PM
i don't WANT to know!

Bobby D
12-17-2012, 09:57 AM
I donít want my wife to know

12-17-2012, 06:14 PM
I don't have a wife anymore...
But that's why I now have a Donzi!