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S/V Laura Ellen
07-10-2006, 03:55 PM
I made an attempt today to remove the fasteners on s/v Laura Ellen. I can now officially say that it isn't going to be easy. The screws are so badly corroded they can't be backed out. I tried to drill the screw heads, but this didn't work well.

At this point I'm thinking the best option would be:
1. use a plug cutter to remove the plank from the fasteners.
2. remove the screws and plug of wood left behind
3. drill out the old screw hole and plug with a dowel (set in epoxy).
4. cut new plank (using old plank as a template to cut new plank)
5. install new plank

Am is missing something? Is there some way of getting these old screws out without destroying the plank?

Any advice would be much appreciated.

cs
07-10-2006, 03:58 PM
I wonder if you can take something like a dremmal and cut a slot in the screw head and than remove with slotted screwdriver? I've done that a time or two on stripped screws.

Chad

Lew Barrett
07-10-2006, 04:00 PM
No advice beyond all the prior discussion, bit I feel your pain.
Lew

Tom Robb
07-10-2006, 04:17 PM
Someone sells what looks like a roll pin with saw teeth filed in the end. Making your own ought to be fairly simple. Sears sells screw removers too. I've never had any luck with Easy-Outs and their ilk. Others' experience may vary.
Anyway you chuck it into the drill and sort of cut the whole sorry mess out. Plug & refasten. Here's a nice example of why rivets are so nice to deal with, especially in a repair situation.

Ken Hutchins
07-10-2006, 04:48 PM
Before touching with any kind of removal tool, Hit the head of the screw with a flat punch and hammer, the punch should be close to the diameter of the screw head and make sure it is sitting flat on the screw before hitting it. The shock will loosen the screw. Also as Chad said use the dremmel if necessary.

S/V Laura Ellen
07-10-2006, 04:57 PM
Did I mention that the screws are badly coroded? On most fasteners I can't find the slot. I've tried to drill a couple of the screw heads but the head just falls apart on one side of the head making it very hard to remove the entire screw head. My plan was to drill the head off and to use "un-screwum" screw extractors to pull the rest of the screw back out.

So far everything I've tried (I've tried the obvious things) has not worked, any other suggestions?

Torna
07-10-2006, 05:21 PM
You might try fashioning a drill guide. It's a short piece of tubing whose ouside diameter is matched (machined) to the size of the countersink (bung hole) that your screw is sitting in, and whose inside diameter is matched to the drill bit you'll be using. You insert the tubing into the bung hole (hopefully it's a somewhat snug fit) and then insert the drill through the tubing. The tubing holds your bit from wandering off center.
You might then have two possibilities:
1) Use a small drill bit and drill a hole down into the screw shank and then use an easy-out screw extractor.
2) If the screw shank is too far gone for easy outs, use a bit just a tad larger then the screw's shank. Arrange the length of the drill guide and the bit's protrusion from the chuck so that will it only cut through the head and slightly into the shank. That way you should be able to remove the heads from the screws. You might then be able to pop the plank off over the screw shanks without too much damage.

Then (hopefully) the screw shank left protruding from the frame is solid enough to get some vice grips on it and twist it out of the frame.

-leif

Lew Barrett
07-10-2006, 05:41 PM
You did, which is why I feel great empathy; Then there's this thread for those who've forgotten;)

http://www.woodenboat-ubb.com/vbulletin/upload/showthread.php?t=51939&highlight=fasteners

Allen, I know you are looking for some new ideas that haven't been previously mentioned. Frequently I think that what's between me and the successful completion of any restoration job that would otherwise seem simple (if tedious) is the odious vision of removing the pieces that are corroded and glued by time and wear onto the old boat. Time is a mean master.

Lew



Did I mention that the screws are badly coroded? On most fasteners I can't find the slot......... My plan was to drill the head off and to use "un-screwum" screw extractors to pull the rest of the screw back out.
So far everything I've tried (I've tried the obvious things) has not worked, any other suggestions?

Jay Greer
07-10-2006, 09:52 PM
Some times it is just necessary to remove the old plank by any method that works without damaging the sorrounding structure.
Japanese pull saws work very well for this. They allow for working in the frame bays accuratly. I usually bore a hole in the plank that can be used to start a Japanese key hole saw. Then, using a gouge or chisel, I knock off the wood arround the fastenings, finally using vise grips to remove the screws.
However I often will try removing the fastenings first by using a Jewler's graver to carve a new slot in damaged fastners. Another tool that works amazingly well are the screw removers called "Unscrewums". I don't waste time using the old plank as a pattern unless it comes free clean. It is often quicker just to spile a new one.
JG

pipefitter
07-10-2006, 10:08 PM
There is a tool that is called a roto-broach. If the heads are gone you can drill i 1/16th" divot in the middle of the screw and the broach will eat the head off clean and they cut amazingly well. The ones I have are made by Hougen and I use them to cut spot welds in sheet metal with. I have used them to remove screw heads before. The pilot pin is spring loaded which is why the divot,or you can use one of those spring loaded center punches to make the divot as well,depending on how hard the metal the fastener is made of.

pipefitter
07-10-2006, 10:38 PM
There is a tool that is called a roto-broach. If the heads are gone you can drill i 1/16th" divot in the middle of the screw and the broach will eat the head off clean and they cut amazingly well. The ones I have are made by Hougen and I use them to cut spot welds in sheet metal with. I have used them to remove screw heads before. The pilot pin is spring loaded which is why the divot,or you can use one of those spring loaded center punches to make the divot as well,depending on how hard the metal the fastener is made of.

S/V Laura Ellen
07-11-2006, 04:59 PM
I was able to remove some planks today. I used the hole saw method since the planks had been marked for replacement. Based on the planks I removed so far, I will probably be replacing all the planking. The iron sickness has softened the wood too much around each on the fasteners. With all this work is doesn't make sense to put the old planks back on it they are marginal. The good news it that the ribs appear to be in good shape so far.

I've ordered (back on June 15) Un-Screwums from TLTOOLS (the manufacturer), and have been told that they are back ordered and won't be shipped until later this week.

Lief - I will be making up a jig based on your description. I hope to have the jig made by mid next week and give it a try as soon as its made. It may me the answer to getting the half corroded screw heads removed.

Pipefitter - I located a dealer for rotobroach bits across the river in Michigan. I will head over to check then out to see if they will help.

I'll post pictures tomorrow. Thanks for the advise and words of support, sympathy and the occasional "I told you so".

Dave Fleming
07-11-2006, 07:10 PM
How difficult is it to get inside the hull?
Can you access the planking that way? Perhaps not all of it but, a goodly portion?


When they came on the scene Milwaukee Sawzalls were a God Send for plank removal.:D

S/V Laura Ellen
07-11-2006, 07:42 PM
There is ceiling (is that the correct term?) installed on most of the boat.
The plug cutter technique of removing the planks is very quick. Should be no problem using a sawzall from the outside of the hull, its not difficult to tell where the ribs are since the paint has been stripped.

I will say that its great to be working on the boat again.

What are your thoughts on painting the ribs with CPES prior to re-planking? I'm not interested into a lengthy discussion about the pros and cons of using CPES, just as it applies to treating old ribs. I had originally thought that painting the ribs with red lead was the way to go.

Should I be concerned about leaving the remnants of old screws in the ribs?

Dave Fleming
07-11-2006, 08:33 PM
Can't say yea or nay about Cpxx. Never have used the stuff.

If those old fasteners are arhn, I'd be inclined to remove as much of them as possible without destroying the Frames.

katiedobe
07-11-2006, 08:51 PM
Torna's suggestion of a guide is good but go buy a "reverse directions" drill bit. It is a twist drill bit that is twisted left handed. You put it in the drill and run the drill in reverse and it drills into the screw, usually it binds and then backs out the screw. Works on the same principle as an Easy Out but in my experience works better. Get 5 or 6 as they sometimes break off in the screw. Also banging the head of the screw before hand helps to loosen things up. You can buy them from Wink's hardware in Portland, OR. Wink's ships via UPS.
Wink's Hardware, SE Stark St and 3rd ave, Portland, OR 97228. Phone: 503-227-5536.

Ed Harrow
07-11-2006, 09:14 PM
Jimmy's suggestion is a good one (Left-handed bits). I got the ones I used from McMaster Carr. Getting out old screws is um, well I'm still too polite to describe it appropriately ;) .

I've made screw removers with nothing more than a roll pin of a suitable ID by filing a notch in the end, at the split, with a triangular file.

pipefitter
07-12-2006, 12:51 AM
Another more user friendly option to the sawzall(which is a good idea) is the air powered reciprocating saws fit with a standard 18tpi hacksaw blade with the teeth directed to work on the pull stroke as are the sawzall blades. The dufference is liken to the difference between a filet knife and a butcher knife. Air powered flush cutting saw is what you end up with. You don't have to buy the little keyhole blades that come with the saw. Hacksaw blades sized to any length with a pair of tin snips kicks butt on an air saw.

Roto broaches or annular cutters(very sharp and I love the way the spring loaded pin shoots the little puck out) cut machine quality holes in wood/metal or plastic with much more precision than the typical hole saws. they do have depth limitations though but even if they don't work for your fastener heads, you will find many uses for them.
http://www.durabore.com/images/annular-cutter.jpg

This is the kit that I have.
http://www.hougen.com/cutters/sheetmetal/images/rotacut-sm-shadow.jpg