Tight screws

My approach for screws that won't budge is as as follows. First try a screw diver with a wise grip or wrench for added leverage. If the screw driver tip comes out of the slots with the added torque I spray Kroil oil and let it sit over night and capillary action will allow the oil to penetrate on horizontal screws . You can put plastic under the screws to protect the rubber roof. If they still don't budge I use Matt's approach with heat except I don't have a high wattage iron so I heat the shank of an old screw driver with a propane torch and let the heat transfer to the screw. The glass transition temperature for most epoxies and polyesters is 350 degrees or less. As Matt said it does not take a lot of heat to break them free. They are only threaded into a piece of sht mtl that is .030 to .050 thick so there is not a lot of surface area to hold that screw into. Let us know how you are making out.

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I have used an 18V cordless drill set on its highest torque setting with a good screw driver bit on screws that I could not loosen by hand. Drill has much more "immediate" torque than can be applied by hand.

Matt_Colie wrote:
You can believe it or don't, I don't actually care. I did work on other people's expensive boats for years before the depression. I did this all the time with screws that were stuck in fiber glass. sometimes some yahoo had used "thread restorer" and other times is was epoxy - even JB-Weld. Heat will make it loose its grip and the screws same screws can be put back in the same holes when you are finished. It only takes about 300°F to get them loose. This is why I specifically said to heat the fastener. I didn't think I would have to say heat only the fastener. That is why a torch won't do the job.

If by the same token, you drill the heads through (on something like a A/C cover) you will not have enough left to grab with vice grips once your pry the cover off. Then you will have unstable parts to try to drill out and you will have to think of some way to replace the threads you destroyed in the process. erial.

Do as you please, as long as I'm not paying for the job, I don't care.

Matt

The main problem with your method is that the covers are NOT fiberglass. Fiberglass can withstand quite a bit of heat. These covers are made from heat formed polymer plastic and will soften and deform with heat.
These are sheet metal screws and that although you may not have much left of the heads, once the cover is removed by cutting off the screw heads, the threaded portion of the screw, that sticks through the sheet metal base is easy to grip with pliers to remove the complete screw. No need to drill them out and damage the threads. Once the cover is removed there will probably be 1/2" of the screw thread to grip with pliers that is sticking through the metal base.

They do rust. Do not be afraid to put some effort on them only 3 things can happen.

1: Strip out screw heads (and/or damage screwdriver)
2: they break
3: they come out

If 1: If the screwdriver sufferes. have it re-sharpened (yes, can be done)
1B: If screw head strips out.. Drill as suggested above and use Vice Grips
2: If it breaks you may be able to get to the top of screw with vice grips or drill it out and go to a slightly larger screw, stainless if possible
3: no problem.

I ended up having to buy the plenum pieces that held the screw sockets because most of mine were seized.

Matt has some very good advice. If you do ruin the tabs, you can make some new ones out of heaver material, and pop rivet them to the AC base, then drill new holes. You could even use light weight angle made of S.S., or aluminum. If the holes through the AC cover get damaged, you can use "Fender Washers" to cover the damaged area.

Good luck

You can believe it or don't, I don't actually care. I did work on other people's expensive boats for years before the depression. I did this all the time with screws that were stuck in fiber glass. sometimes some yahoo had used "thread restorer" and other times is was epoxy - even JB-Weld. Heat will make it loose its grip and the screws same screws can be put back in the same holes when you are finished. It only takes about 300°F to get them loose. This is why I specifically said to heat the fastener. I didn't think I would have to say heat only the fastener. That is why a torch won't do the job.

If by the same token, you drill the heads through (on something like a A/C cover) you will not have enough left to grab with vice grips once your pry the cover off. Then you will have unstable parts to try to drill out and you will have to think of some way to replace the threads you destroyed in the process.

Do as you please, as long as I'm not paying for the job, I don't care.

Matt

Use vise grips on the heads. If the twist off, use an extractor to remove the shafts.

Matt_Colie wrote:
I can't imagine why someone would use a thread locker on those fasteners, but I have run into stranger things. They also may have ripped the threads out and replaced them with an epoxy and no release coating. This will be a real PITA, but it will work if the screws were set in Lokite or other.... Get a tarp and a soldering gun or iron (a torch won't be confined enough). Heat the fastener as long as you dare and then try to loosen it. If that doesn't work, heat it longer than you think it can stand and try again. You need to trap because any breeze will take all the heat away.

The advantage of this method is that it is non-destructive.

Matt

It may be non destructive to the screws, which cost pennies, but it will probably damage the PLASTIC cover, that cost around $100.