Frozen SS Screws Securing Winch to Mast

[michaeld]

We are looking to replace a Barient 25 main halyard winch on our mast. The winch base was secured with five simple SS screws. As you may already correctly assume, the screws are frozen into the mast mounting bracket. Photos attached. I am confident that I am not the first with this issue. At this time, I have tried heating with a propane torch along with an impact driver resulting in nothing more than ruining the driver tip. Someone must have a solution. I am looking for advice.

[thinwater]

A week-long soak with PB Blaster. Then MORE heat.


No, you are not the first. Mast winches can be epic.

[Orion Jim]

Acetylene gets much hotter than propane. It’s worked for me.

[coopec43]

I'm sure the previous advice is good but others have had the same problem too. Maybe there's some ideas here?


https://www.samsmarine.com/forums/sh...ed-in-Aluminum


Clive

[Calif.Ted]

I like a 1/2 drive Phillips head socket on a long breaker bar, little more control than the impact driver.

[roverhi]

You might try the jumper cable trick. Hook jumper cables up to the battery as you normally would. On the other end put a bolt (1/4" x 2" bolt works fine) in the postive lead clamp of the jumper cable. Clamp the negative lead as close to the offending bolt as possible. Touch the bolt in the positive lead clamp to the head of the fastener. You set up what is essentially an arc welder. Will heat the fastener to a cherry red if left in contact long enough. It also gets the fastener way hotter than you can with a MAPP torch. It works really well as it only heat up the area of the fastener and not burning up the surrounding country side like you do with a torch. It is really the only way to get serious heat to a fastener if there is painted surfaces or plastics close by. Quench the heated fastener with penetrating oil. Try to remove the fastener with an impact driver, either manual or power. Repeat the process till you break the fastener loose. Other than using the trick to remove all the fasteners on a 44 year old mast, used it to get corrosion welded bolts out that passed through substantial aluminum castings on my self steering vane.

Having said the above, the hardest fastener to remove is not one that is threaded into aluminum but one that simply passes through an aluminum casting like cleats, etc. Getting the bolts out of the self steering casting took something north of 25 iterations, heating with the jumper cable and quenching with penetrating oil over many days. A good idea to coat the shaft of any fastener in aluminum cleats or castings with Lanocote.

[JPA Cate]

michaeld,

They're giving you the straight skinny. It is really amazing to me, I found out about all this back in the '80's. You might think manufacturers would routinely use lanolin or Duralac or aluminum anti-seize (all available before then, and all work) in the putting together of the rigs, but "they" don't.

Back in '83, we met a guy who field stripped a brand new outboard, and put it back together with anti-seize. Never had a problem working on it. Smart fellow.

Heat and cold, and cursing. What Jim has been using for penetrating oil lately is a 1/2 and 1/2 mix of acetone and automatic transmission fluid. He heard about it here on CF, and it has worked well on what we've tried it on (but we don't have the same dissimilar metals corrosion you're dealing with with the aluminum with s/s screws into it on your mast).

Ann

[Marqus]

Originally Posted by roverhi

Touch the bolt in the positive lead clamp to the head of the fastener. You set up what is essentially an arc welder. Will heat the fastener to a cherry red if left in contact long enough.

Heard of this but haven't done it myself, so just wondering, Peter, from your experience, how long are we talking here keeping the short going - should you limit it to something like 5 seconds or can you go 20 seconds or more ?

Also, should one use an old battery, or will your normal start battery not suffer any adverse effects from a 20 second dead short ?

[Suijin]

Just a note when you reassemble. As recommended use Lanacote or Tef-gel or similar and use A LOT. While they have some anti-corrosion additives they work primarily by keeping water out of the interface between the metals. You want to coat all mating surfaces generously.

In my experience Tef-gel lasts longer than Lanacote but if you already have Lanacote use it.

If time is on your side I would escalate your efforts incrementally. I’d start with Thinwater’s approach. You might get lucky.

[svJasmine]

Use pb blaster and an impact screwdriver. The kind you beat on with a hammer. It will work.

[Mikado]

Originally Posted by svJasmine

Use pb blaster and an impact screwdriver. The kind you beat on with a hammer. It will work.

Agree with Jasmine, but heat with mapp gas torch. The heat is critical for success.

[George DuBose]

All of the above recommendations may or may not work or may take an inordinate amount of time and effort.

My solution when I removed the 1973 Lewmar wire winch to be replaced by a modern self-tailer was to use my Dremel with round or conical grinding stones and grind off the heads of the stainless machine screws. Then I took my belt sander and sanded all the remaining screw shafts flush with the aluminum winch pad that was welded to the mast.

I then bored new holes in new positions and tapped them to accept stainless steel helicoils that had an ID of the new machine screws. This step avoids any future corrosion between the screws and the helicoils. Needless to say that the helicoil will fix themselves to the aluminum mast pad with aluminum oxide.

PB Blaster and other potions work sometimes, but not everytime and often take quite a while to work.

This method avoids the danger of playing with batteries, jumper cables and acetylene torches.

I had a similar problem with the screws that held the boom end caps. I had to drill out several of the 12 screws and that often led to damaging the original holes in the boom. I made the holes larger and used larger machine screws, swapping the single slot round head screw for screws with hex heads and liberally coated them with Lanocote. Yearly maintenance now includes turning these 12 screws out a bit and retightening to avoid aluminum oxide buildup.

[Foredeck]

Daily lurker, seldom poster: I had this problem - BP Blaster & impact failed, & unlikely as it sounds, found a site that said “soak them in white vinegar”.

Did so - it took some time, but galvanic corrosion was defeated with this, and the bolts came out with a (determined) screw driver.

It has also been suggested that CLR - the original, has the same, but stronger properties than white vinegar. Haven’t tried this yet, so can’t comment. Anyone who does, please advise.

[_andi_]

couple of more options:

• (ideally brass) punch and big hammer directly on the boldhead. couple of whacks crush corrosion / bend the three threads/windings which actually hold the bolt.
• bigger impact. the heads look well to nice still. and it's normal to waste a couple of tips, most of them are cheese grade steel.
• screw driver with decent shaft + hammer on an angle, like turning it by hammering. probably won't work here, difficult to tell from a photo. but often the best way to open large flatheads.
• when all the heads finally broke: even out with grinder, center punch and drill. Either remove the stubs with vise grips or drill them out too.
• In case you damage the threads there's a couple of options: nutserts, helicoil, timesert, tapping next larger size, ...

I'm personally not a big fan of heat but another method to put in heat fast (which you need to in aluminum bc its a good heat conductor) is a welder.

[Cheechako]

Get a decent size center punch. Bang each screw hard. See if it loosens.. but my guess is no way, especially with those crazy slot head screws.
I would:
- center punch each one.
-Drill out the head only to get the head to fall off..
-Remove the winch.
-Cut each remaining stud flush with a hack saw. (or try some good vice grips!)
-Put the new winch on on rotated from those old holes.
-You can try to drill out the bolts but in aluminum most often it drifts into the soft aluminum and makes a mess.