Trim Tab Problem - Broken Screws, Tabs Stuck On!!! - The Hull Truth

mr_mbuna · 04-12-2005, 04:30 PM

We were painting our Pursuit 2470 this past weekend for the second season. We painted the aluninum trim tabs last season, accidentally, so we wanted to take them off the boat and strip the paint off them because anti-fouling paint is corrosive to aluminum. The tabs are factory installed. They are held in by six or so Philips head screws. The screws snapped - almost all of them - about 3/4 of the way down. Don't ask me why we didn't stop after the first snapped screw - oops. And then, even after we got all the screw heads out, the tabs would not come off the boat - it seems like they are glued on or something.

First, what do we do about the broken screws?

Second, what do we do about the tabs being stuck to the boat?

I'd sooner leave the tabs on the boat and just do our best to strip the paint off them as-is - there's enough room to manuever and clean both sides. But now there's broken screw ends stuck in the bottom of each of the holes.

This is turning out to be a big mess

evernic · 04-12-2005, 04:32 PM

I have never heard of Aluminum trim tabs, anybody else

i guess anything is possible but, I wouldn't expect this from pursuit

nsh · 04-12-2005, 04:36 PM

It they were installed using 3M 5200 ii dont know how you would go about getting them off. You may want to try heating up the metal part of the tab that is flat against the boat. It may melt some of the adhesive that is holding the tab in place. Dont over heat it and burn anything. Once you warm it up get a big head screwdriver between the tab and boat and start putting slight pressure on the screwdriver. This may help to get it started. Once the tab comes off you may have enough room to grab the broken screws with a pair of vice grips. Also, you sure those tabs are aluminum. I know of stainless tabs but rarely aluminum. Thats about all of the advice i can give at this time.

cjd · 04-12-2005, 04:37 PM

If it where me, I would do what I had to do to get the tabs off so you can deal with the broken screws. You will want to fill those holes with some kind of resin/dowel solution, and get a good patch over the holes. Then I would just reinstall the tabs over an inch or so with fresh screw holes.
I have several screws in my transom, and I just bored out the holes, filled with resin, then reinserted new screws with 5200. Im not pressed about appearance, but I don't want any leaks in the transom.

Others wiull have more detailed advice, but Im not sure how you can fix this right without taking the tabs off and dealing with the half screwed holes

mr_mbuna · 04-12-2005, 05:22 PM

The tabs may not be aluminum - but we thought they are.

They are Pursuit original equipment, so I'm sure its whatever it should be. We don't really need to remove the tabs to strip them, if its hard to take them off. We just thought it would be convenient - boy were we wrong. I definately don't want to remove them if they're permanently epoxied on - that'd be a real mess of the hull. And the screw ends are the only thing left in the boat, deep in the holes.

I think the real issue here may be that the tab plates are installed in recessed areas engineered specifically for them. Can't move the plates.

I've emailed Pursuit for their advice.

salty_dog · 04-12-2005, 05:42 PM

I have your boat and you are not going to be able to move the tabs. As you mentioned the pockets will prevent you from doing so. You are going to have to remove the tabs. Going from memory here, the boat is in the water now. You will need to get some very strong single strand wire, 300 pond wire leader should work. I believe the holding plate is bedded with 5200 as well as being screwed in. Assuming the screws broke below the mounting bracket, get the wire under a corner of the mounting plate and work it back and forth to break the bond with the 5200. I doubt any amount of heat is going to be that effective. Once you get the tabs off, you are going to need to drill out the broken screws, if they broke well down into the hole, you job will be a lot easier. If you can get the broken srews out cleanly you have an easier option, replace with a larger diameter screw. If they do not come out cleanly, I would overdrill the hole and then epoxy the hole using a syringe. Be sure to get the epoxy as deep into the hole as possible. Then remount the tabs.

The tabs are stainless steel, don't worry about the paint on the tabs, it will most likely wear off with use. Certailnly won't harm them.

Reel-Rascals · 04-12-2005, 05:53 PM

Tabs by Lenco and Bennett are 304 series stainless steel. If the installer used 5200, try Anti-Bond 2015, asolvent made to disolve 5200. I saw John Griviskis of Ship Shape TV use it to remove a huge OB bracket off a trasom that was fully sealed around the edges and backing with with 5200, assisted with the "wire trick" Salty-Dog mentions above.

I wouldn't spray the Anti-Bond 2015 either, which would waste it, and it ain't cheap. I'd use either a putty knife or cardboard knife to score the top edge and would weep in Anti-Bond using a syringe.

To prevent this from happening again, I'd drill out the screws to a hole at least 2x the size of the fastener or more and would wet them out with CPES epoxy injected by a syringe. Once kicked, mix up some epoxy with filler added to peanut butter consistency and put into hole, starting from the back, also with a syringe (heavier one).

Then you can tap drill the epoxy "plug" to hold new screws. The epoxy will protect the core in case water ever gets in. I myself still use 5200 below the waterline, but for screws, I run them through a wax candle before installing and wipe them clean on a rag so there's no wax pieces visible. This allows the 5200 to cure and seal, but the wax stays as enough of a release agent to allow them to be removed if/when needed.
FWIW before I installed my Bennett tab plates that mount to the hull, I degreased and waxed the side of the SS plate that rests against the hull. I also use enough 5200 so that it goops out around the edges and seals in place. Works for me ...

salty_dog · 04-12-2005, 05:57 PM

Don't worry to much about the core where the plates are mounted. It is solid glass. About 3/4" thick. I just cut through the area to install a thru hull transducer. Just wanted to give you some peace of mind. Reel's advise is very good.

BW23 · 04-12-2005, 11:24 PM

Im in the process of increasing the size of my "planes"and recently experiences similar problems. No broken off screws but the hinge shim plate was stuck /glued to the transom.

1 side came off quite easy, I muscled the other and tore off the gelcoat down to the glass.

Reapired with Marine Tex since it will be cover by the new hinge.

Proceed slowly so you don't create more work for yourself.

mr_mbuna · 04-19-2005, 12:45 PM

So we were thinking of approaching the problem this way... we don't have any real need to take the trim tabs off except to strip them, and that's not worth the effort described above.

What if we get a syringe, fill the screw holes with epoxy, and just reinsert the screws into the wet epoxy and let it dry?

Upside... minimal work. Zero water leakage since screws are epoxied in. Downside... screws are permanently installed.

mr_mbuna · 04-19-2005, 12:45 PM

So we were thinking of approaching the problem this way... we don't have any real need to take the trim tabs off except to strip them, and that's not worth the effort described above.

What if we get a syringe, fill the screw holes with epoxy, and just reinsert the screws into the wet epoxy and let it dry?

Upside... minimal work. Zero water leakage since screws are epoxied in. Downside... screws are permanently installed.

Tyee 2 · 04-19-2005, 01:25 PM

If that was my boat, those holes would be sealed and a new set of holes would be drilled about an inch beside the old holes. New SS screws installed and you should be good to go

.
Keep in mind, those tabs take a beating. They need to be mechanically atached to the hull. Don't trust that 'glue' will hold them on!

Good luck... Tyee.

mr_mbuna · 04-19-2005, 05:46 PM

Tyee - one, I'd bet that epoxy is stronger than screws. Two, as said earlier, the tabs sit in recessed mounting areas. Only option is to drill out the hole bigger and put in new larger screws, to get a "mechanical connection."

dclark · 04-19-2005, 06:10 PM

Recent experience with 5200 is it will soften with heat. Marine dealer removed my leaning post which was screwed and glued. Used a heat gun heated the metal and softened the glue. Took about an hour to get the set loose but it will eventually soften.

Rags · 04-19-2005, 06:40 PM

Mr_mbuna - if you can get the srews out to fill them with epoxy, why would you want to put the small screws back in and set them in the epoxy?
Use larger screws and be done with it...or as said previous in this thread, fill existing holes and drill new one about 1" away.
Don't trust just epoxy or 5200 it will eventually fail. There's a great deal of water pressure on those tabs and vibrations and pounding will loosen the leading edge of the tab until it begins to peel away from the hull. The screws will maintain adheasion on the leading edge.

rwidman · 04-20-2005, 07:43 AM

Since you can't move the tabs and you can't get them off either, how about filling the holes with your favorite sealant and then drilling new holes through the tab mounting surface and into the transome? Drill the holes through the tab mounting plate large enough to clear the threads of the screws (use a drill stop to get the correct depth), then switch to a smaller drill bit for the transom.