Removing seized SS screws from aluminum

[Finnerty]

What are the options for removing SS screws from corroded aluminum? I want to remove an aluminum angle bar from the transom of my fiberglass boat (used to support the swim platform) that has been screwed into the hull using SS screws. I tried heating the screws with the tip of a soldering iron first, but no luck. If I grind them out will the heat damage the fiberglass? Aesthetics aren't a problem cause I can epoxy over the scars and they will be covered up under the new swim platform.

 

[britisher]

Re: Removing seized SS screws from aluminum

I suppose you could clean up the area with a wire brush, then liberally spray with something like PB Blaster and just give it time to work. Stainless Steel screws are, to my understanding, not as strong as plain steel. On my resto last year, the PO had screwed some hinges on to the GF transom area. They were Phillips head which rounded as quickly as you looked at them. A couple came out, but most of them appeared to loosen, only to shear off. I ended up drilling them out of the GF, then filling in the holes with PB.

 

[wrench 3]

Re: Removing seized SS screws from aluminum

In my experience, any good penetrating oil left to soak for a day works wonders. As for grinding, If you go in short bursts and let it cool in between, it shouldn't do any damage.

 

[kfa4303]

Re: Removing seized SS screws from aluminum

+1. Penetrating oil, heat and patience are your best bets. I would avoid using the various "easy-out" gizmos as they rarely work as advertised and can often get stuck in the work, or break off.

 

[minuteman62-64]

Re: Removing seized SS screws from aluminum

Stainless Steel screws are, to my understanding, not as strong as plain steel.

My cutting tools tell me SS is harder than mild steel. The specs. I've seen say is stronger. Nevertheless, my experience has been that I'm in the same boat with either mild steel or ss - it is either going to break loose or shear off. I'm not real patient so I let some penetrating oil soak in and then hit the fastener with my 18V impact tool. A lot break loose. Some shear off and I figure they would have sheared off anyways - then start with the drill.

 

[kfa4303]

Re: Removing seized SS screws from aluminum

ss is stronger, but it can still break. hopefully, the impact tool will do the trick, but we've all had to resort to dirt tricks to get out old bolts and the like.

 

[minuteman62-64]

Re: Removing seized SS screws from aluminum

ss is stronger, but it can still break. hopefully, the impact tool will do the trick, but we've all had to resort to dirt tricks to get out old bolts and the like.

Yeah. After a recent struggle removing the bow seat on my boat (1982 era cad plated machine screws and nuts fastening plywood to aluminum) I'm thinking of investing in some left-handed drill bits. I priced them at Enco. Yikes! No set less than $150. HF has a set that goes to 1/4 inch, for about $10. I've never been impressed with Chinese steel, but, for that price I can buy a set and throw them away after a few uses.

 

[Daniel1947]

Re: Removing seized SS screws from aluminum

As an old mechanic, I have always found that if you first turn the corroded screw...or nut...or bolt clockwise, like you are going to tighten it, in many instances it will break loose when you turn it to remove it. You want to apply just enough torque to start tightening. Problem with stuck screws is that the first turn to loosen usually starts stripping out the slots, but I am sure you already know that. My other suggestion is to use the left handed drill bit. Drilling a hole completely through the complete length will sometimes relieve some of the pressure exerted against the threads. Just hope some of this helps.