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Removing cross beam bolts.
Posted: August 14th, 2012, 2:59 pm
by culcoinc
I'm looking for input on removing the inner bolts attaching the cross beams to the hulls. They are roughly 9" inside the beam and I have no idea how to access them. The outer bolts are pretty accessible but really hard to get out although they did come out. I have a SC 17 that I need to do hull repair and maintenance to and I thought it would be easier to work on in pieces rather than in one piece. Any help would be greatly appreiciated.
Re: Removing cross beam bolts.
Posted: August 14th, 2012, 7:27 pm
by Matt Haberman
There is a hole on the top of the beam right above the beam bolt, it might have a plastic plug in it. A 1/4" ratchet extension will fit through that hole. You will need to put the socket in the end of the beam by hand and put it on that bolt, then plug the extension in from the top.
Re: Removing cross beam bolts.
Posted: August 14th, 2012, 9:03 pm
by havliii
You will likely snap a 1/4 inch ratchet extension. I had to oversize the hole on top of the beam to fit a 1/2 inch ratchet extension and use a long handled ratchet to get three of the inner bolts out, the fourth bolt was totally seized and snapped off. I then had to drill the remaining bolt close to max diameter and chase the threads. Aluminum and stainless are a terrific dielectric battery and create gobs of corrosion that acts as a great loctite.
The story has a happy ending, my boat was repaired and has been sailed hard for the last two seasons, over 65 day trips on her since the repairs.
Re: Removing cross beam bolts.
Posted: August 15th, 2012, 1:37 pm
by gahamby
IMGP1758 half moon blocks.jpg
A true pain that. I used lots of PB Blaster and kept a rag handy. I had to enlarge the access holes. Try to size the hole for a Heyco plastic knockout cover.
http://www.heyco.com/Hole_Plugs/
I sanded the half moon blocks bright and primed them with Moller Zinc Chromate primer (West Marine). Re-tapped the holes with a
3/8-16 tap. I am going to treat the new bolts with Ideal Noalox joint compound. I use this product in electrical panels to prevent corrosion between aluminum and copper. I don't know if a bedding compound is needed under the half moons or the crossbar. GH
Re: Removing cross beam bolts.
Posted: August 15th, 2012, 9:51 pm
by culcoinc
Thanks everyone for the input. Matt are the boats assembled with holes and plastic plugs in the beams because mine has the holes directly above the bolts on the front beam but not the back beam. The previous owner had removed the front beam to do some kind of repair where the beam meets the hulls on both sides so I had assumed he had drilled those holes. Based on the rear beam having no holes I would assume when originally assembled they use a pneaumatic ratchet that would reach inside the beam to the bolt. I was hoping to avoid drilling holes if possible because every hole weakens the beam but that seems to be way. Thanks again for everyones input. Hey Havliii have you ever put your boat in Lake of the Woods, my sister has a house there?
Re: Removing cross beam bolts.
Posted: August 15th, 2012, 10:15 pm
by havliii
No, I haven't launched at LOW, while Lake of the Woods is close by, my taste runs to larger bodies of water and bigger wind. Most of my sailing is on the Chesapeake Bay, Potomac and Rappahannock Rivers down the Northern Neck. You'll find that the SuperCats cover a lot of ground quickly and need room to roam! On a typical daysail we'll cover 30-40 miles. We have three SC-19's that run together and a SC-15 that comes out to play, throw in some Prindles and a G-Cat or two, a Hobie here and there and that describes our non-club.
Robert posted a lot of stuff about his restoration of his 19 on this board.
Congrats to G. Hanby, looking forward to seeing your SC15 soon!
Everyone is welcome to come sailing if you're in the neighborhood.
Re: Removing cross beam bolts.
Posted: August 16th, 2012, 9:38 pm
by Matt Haberman
As far back I can remember the 15, 17 & 19 always h a 3/8" diameter located above the inner beam bolt for assembly. Was the beam possibly replaced at some point in time?
Re: Removing cross beam bolts.
Posted: August 17th, 2012, 4:12 pm
by gahamby
Yep, it's a 3/8ths hole alright, it won't quite take a 3/8ths extension. The bolts on my 15 were real stubborn. A 1/2 ratchet was the ticket. What is the torque spec for that bolt, besides tight but don't strip it out.
Re: Removing cross beam bolts.
Posted: August 18th, 2012, 11:33 am
by Matt Haberman
Off the top of my head I don't have a torque spec for you, but what we usually tell people is to use a 3" mini ratchet wrench and tighten the bolts snuggly by hand. Then after sailing the boat for 4-6 hours to re-thighten them again. If you repeat this a couple of times you will find that they usually don't get any tighter after the 2nd or 3rd time.p