Heat or not to removed seized screws?

[Paarrothead]

Originally Posted by sailingdog

Do not heat an aluminum spar if you can avoid it. Heating an aluminum spar will remove the tempering that gives it most of its strength. Most aluminum spars are heat treated alloys.

Manufacturing Engineer here. This advise is correct. Alum alloys temper out at low levels of heat. Drill out the screws and replace with Helicoil inserts and use anti seize compound. Your issues will be over for the life of the boat afterwards.

[bljones]

Ditto on the impact driver. As a last resort, drill and tap. Don't even get me started on "Easy-outs." A tool with a two word, and two lie, name.

[Maine Sail]

I have removed lots of screws suffering from stainless/aluminum corrosion over the years. There is no panacea that I hove found as of yet. Heat on spars is not a good method or practice....

Be very, very, very careful as the stainless is soft and impact screw drivers can often just twist the heads off before breaking the bond. I have found impact to be the best method but in the form of a cordless impact driver with about 1200+ beats per minute. These BPM's tend to fracture the white, nearly welded corrosion, with less chance of twisting the head of the screw off before it finally gives up its hold. This is not to say you won't twist off the heads still but I do find the success rate using a cordless impact driver about the highest..

Sadly PB Blaster type products do not tend to work as well on this type of corrosion. A few good taps with a drift in the center of the screw head then an impact driver, not an impact screw driver that you hit with a hammer, I have found to be the best and highest success rate method. Ryobi makes a good inexpensive 18V impact driver..

Good luck stainless/aluminum might as well be welded. Use Tef-Gel when re-installing the screws and they will come out in twenty years with ease..

[hellosailor]

Blaster and impact hammer, amen.

Heat can be a bad thing, detempering metals and starting fires. Instead try extreme cold. Not liquid nitrogen (snap) but CO2 provides a 100F temperature shift and that's usually enough to break things free without breaking them.

Either ice them down with a CO2 extinguisher (expect $20+ to recharge it) and pack them with a slurry of dry ice chips and alcohol. Dry ice, maybe $10 in the supermarket or ice cream store or the local yellow pages.

Ice them down until there's condensate and frost on the metal nearby, then warm them up to room temp. Repeat the cycle 2-3 times then take the impact hammer and they should just spin free without a problem.

Any remaining dry ice can be used to chill the remaining vodka, just make sure to strain that martini before you drink it. :-)

[TQA]

Hey guys read the OP.

It is the end cap on the boom, sooo heat the sucker with a torch, who cares if you loose temper. With heat and an electric impact driver you have a much better chance of shifting those screws.

I agree using enough heat to affect the temper would be a bad idea if it was mid boom but the end cap - no problem!

[ChuckA]

My approach is to warm the surrounding area with a heat gun, and apply ice cubes directly to the screw head. The idea is to expand the base metal while shrinking the screw. A dremel tool with a cut off disc is also handy. If the screw head gets sloppy you can re-slot the head to get a better grip.

[midnightsailor]

While I agree it is worthwhile to know how to go about removing stainless steel screws from aluminum, in this OP's case, I think the real issue is why he needs to remove his mainsail from his boom by removing the end cap and pulling it out from the aft end of the boom. Unless I have been uncannilly lucky with all the boats I have owned or worked on or there is somthing different or special about the Newport 28, I don't see why he just dosn't drop his mainsail and pull it off from the forward end of the boom? He does mention resorting to removing it from the forward end but he also says he had to first remove the boom. Unless I am missing somthing here or this boat has somekind of boom track or slot that I am totallly unfamiliar with, shouldn't he just be able to pull it off the boom from the forward end without removing the boom? I have always been able to do this on any boat I have owned or worked on. Rick

[jaschrumpf]

Originally Posted by midnightsailor

While I agree it is worthwhile to know how to go about removing stainless steel screws from aluminum, in this OP's case, I think the real issue is why he needs to remove his mainsail from his boom by removing the end cap and pulling it out from the aft end of the boom. Unless I have been uncannilly lucky with all the boats I have owned or worked on or there is somthing different or special about the Newport 28, I don't see why he just dosn't drop his mainsail and pull it off from the forward end of the boom? He does mention resorting to removing it from the forward end but he also says he had to first remove the boom. Unless I am missing somthing here or this boat has somekind of boom track or slot that I am totallly unfamiliar with, shouldn't he just be able to pull it off the boom from the forward end without removing the boom? I have always been able to do this on any boat I have owned or worked on. Rick

I took the boom off the boat mostly to get to the screws, because I knew there was no way to work on them with the boom in place. After I got it off I found out that the sail does slide out the forward end, though I"m not sure the slug attached to the clew will come out unless I drop the boom off the gooseneck. This is the first boat I've owned and done maintenance on on, and this is the first time I've taken off the mainsail, so there's lots of "firsts" left for me to do.

So bottom line, unless I need to replace the fitting that attaches to the gooseneck, there's really no reason I need to get these screws/bolts out. So I'm not going to make the effort right now.

And if I ever do decide to do it I'm just going to take it to a shop and let them do it, as I tried using the impact screwdriver after letting the PB Blaster soak on it for a couple of days, and all I could figure what happening is that my hand was rotating 20 degrees in the opposite direction when I hit it with a 3-lb sledge. The slotted screw heads sure weren't going anywhere! I guess I'm just not macho enough.

Thanks for all the advice!

[AnnapolisStar]

Where can you buy an impact driver like the one you have pictured. Does craftsman make one?

[AnnapolisStar]

It has been my experience that on an older boat there is absolutely no hope of ever removing a stainless scew from an aluminum mast. I have never had luck in using easy outs or drilling a stainless screw either without a lot of damage to the surrounding metal. In my experience the only tool to use is a diamond tipped dremel tool. The diamond bit is very small and you can grind the screw down quickly (relatively speaking). After it is gone you must redrill the hole and re tap with a slightly larger screw. The diamond tip bit, however, is hard to find and the actual bit that Dremel makes is nothing but a toy. I have had the best luck at ACE hardware where the larger stores sell diamond bits under a different brand name - they look and work much much better than the dremel bit. The best one I ever found was at Wal Mart where they sold them 2 for $3. I bought one and it was industrial strength but Wal doesn't seem to stock it any more. Once you find one that works be sure to buy out the store because it will be one of the best tools you will ever own.