Removing Coaming Boards

[Duncan]

I finally managed to remove the starboard coaming today, but I had to drill out one of the screws to do it.
None of the screws on the port side want to budge though.
I have been trying to learn how to use a manual impact driver to do this, but without any success so far.
I am convinced that Cape Dory employed 500 lb gorillas to drive these screws!

I DETEST Philips screws, but someone tonight suggested using a rubber band between the bit and the screw, to keep it from demolishing the grooves in the screw head.

Any other suggestions on the impact driver or the ugly Philips screws, or generally how to get the coaming boards off?

[moctrams]

I use the Milwaukee ipact driver.
http://www.cpomilwaukee.com/milwaukee-m ... lt,sc.html

[Jeff D]

I have removed the coamings on both a 22 and TyDS. In neither case did I have any difficulty in removing the philips head screws. I don't mean to be insulting but are you sure that you have the right bit? I have had good luck using an old fashioned brace for difficult screws.

My problem with the coamings was not the screws but the bedding. On the 22 (1982) once the screws were removed the coamings literallly popped off. The TyDS (1985) was a nightmare. Someone had used what I think was 5200 to attach the coamings. After 3 days, several bottles on antibond, a new dremel multimaster, several failed great new ideas I was left with splinters. My winters project of stripping the PO's bad varnish job morphed into fabricating a beutiful set of 9' coamings.

I hope that your project is easier than mine

[Gary H]

When I was installing new toe and rub rails, I stripped a few screws before they were fully set and had to remove them (I probably should have been using an impact driver instead of a drill). I had success with Unscrew-ums. The are bits that when run in reverse grab the outside of the heads of the screws. They are made by T&L Tools and I believe Jamestown Distributors sells them.

[Duncan]

I use the Milwaukee ipact driver.
http://www.cpomilwaukee.com/milwaukee-m ... lt,sc.html

Mine just chews a cone-shaped hole in the screw head

... I don't mean to be insulting but are you sure that you have the right bit? I have had good luck using an old fashioned brace for difficult screws.

My problem with the coamings was not the screws but the bedding...

I have been using Philips bits, of course, but I am going to get a bigger screwdriver, to max out the contact area and the torque
Good call on the brace, I can't recall where mine is, but I will have a look. Getting a wrench on the screwdriver helped with the slot-heads on the stbd side.
No issues with the bedding, I think it's the original (white).

... I had success with Unscrew-ums. The are bits that when run in reverse grab the outside of the heads of the screws. They are made by T&L Tools and I believe Jamestown Distributors sells them.

Good lead, thanks. I have had to drill out several of the Cape Dory screws in various places, but it takes a long time and they usually smoke before they finally give way

[Duncan]

Just to report that the winning technique was the manual impact driver, plus the biggest Phillips screwdriver I could find.

The manual impact driver needed to be pre-loaded (twisted counterclockwise) before being struck.
The big screwdriver has a hole in the handle, so I put another screwdriver through that to make a t-handle.

The boards were badly weathered, but came back fairly well with 80 grit on the power sander.
Planing them might have been a good idea, but I decided they were good enough to start varnishing.

Photos to follow.

[jepomer]

A Phillips screwdriver is made to "cam out". It is good to ensure that the threads won't strip out but at the expense of damaging the screw head. One really wants to have a Frearson screw head. Wikipedia has a nice summary of screwdriver types.

en.wikipedia.org/wiki/List_of_screw_drives
=====
Phillips

Created by Henry F. Phillips, the Phillips screw drive was purposely designed to cam out when the screw stalled,[citation needed] to prevent the fastener damaging the work or the head, instead damaging the driver. This was caused by the relative difficulty in building torque limiting into the early drivers.

The American Screw Company of Providence, Rhode Island was responsible for devising a means of manufacturing the screw, and successfully patented and licensed their method; other screw makers of the 1930s dismissed the Phillips concept because it calls for a relatively complex recessed socket shape in the head of the screw — as distinct from the simple milled slot of a slotted type screw.
Phillips drive sizes (different from the screw size) are designated 0000, 000, 00, 0, 1, 2, 3, and 4 (by order of increasing size).

=====
Frearson

The Frearson screw drive, also known as the Reed and Prince screw drive, is similar to a Phillips but the Frearson has a sharp tip and larger angle in the V shape. One advantage over the Phillips drive is that one driver or bit fits all screw sizes. It is often found in marine hardware and requires a Frearson screwdriver or bit to work properly. The tool recess is a perfect, sharp cross, allowing for higher applied torque, unlike the rounded, tapered Phillips head, which was designed to cam out at high torque. It was developed by an English inventor named Frearson in the 19th century and produced from the late 1930s to the mid-1970s. The Reed & Prince Mfg. Company of Worcester, Massachusetts, was put into bankruptcy in 1987 and liquidated in 1990. Another entity called Reed & Prince Manufacturing Corporation, now of Leominster, Massachusetts, purchased some of the assets including the name at the liquidation sale.

[tjr818]

I have always preferred the Reed & Prince drivers over the Phillips. They are getting much harder too find. I guess the Chinese manufacturers haven't heard of them

[tjr818]

Oops! How do you delete a duplicate post???

[wsfanning]

I recently removed all the teak from my Typhoon. The seat coamings came off remarkably easy but the toerails were pretty difficult. Several of the screws had hit fitting hardware and were bent, obviously factory installed since those bungs were original, and I had to literally tear the teak away and rebuild the damaged area with epoxy. There's no driver that will remove a bent stainless screw, ughh.

[sharkbait]

This is what I use to defeat damages screws. The stainless steel tubing fits in the bung hole and the end mill fits inside the tubing. I use a variable speed drill and just mill off the top of the offending screw. Worked very well when removing all the teak on the Typhoon.

[wsfanning]

@sharkbait, excellent tool. And it's origin please??

[sharkbait]

It is just a short piece of 3/8" stainless tubing with a standard 4 flute end-mill that will fit inside. Available at any machine tool supply house. For the cheap route look to Harbor Freight.

[wsfanning]

Thank you! Hopefully I won't need this until the next boat. But I'm already looking!

[sharkbait]

But I'm already looking!

For the tool or the boat?