[C320-list] Mast thickness

[surprise thompson87.com]

Mine are 34 years old so I guess I can't complain. I've always used Tef-Gel to prevent the aluminum/stainless bonding problem.

T. Scott Thompson
Catalina 320 “Surprise,” #653 (1999)
surprise at thompson87.com

-----Original Message-----
From: C320-list <c320-list-bounces at lists.catalina320.com> On Behalf Of Greg Flanagan via C320-list
Sent: Saturday, May 13, 2023 6:56 PM
To: C320-List at catalina320.com
Cc: Greg Flanagan <greg.flanagan at shaw.ca>
Subject: Re: [C320-list] Mast thickness

I had the same problem. I got a drill bit and tap the next size up. Redrill the hole which will not generate much metal as the next size is about the size of the old tap. The thickness is  only about 3/8” so one needs to tap carefully maintaining a strict perpendicular approach. Aluminum is easy to tap but still use oil while doing this. I went with a fine thread. The cause of the initial problem is a SS machine bolt going into aluminum. The dissimilar metals rots the metal. A friend gave a grease like material (help needed on what this is) to coat the new bolts with before I reassembled the plate. It is now over 10 years and all is well (even better).


Greg
Hoop Dancer #1076
Sidney, BC

> On May 13, 2023, at 3:35 PM, surprise thompson87.com via C320-list <c320-list at lists.catalina320.com> wrote:
> 
> Reinstalling my mainsail yesterday one of the screws attaching the mast track gate plate felt like it stripped. I'll have to drill it out and retap for a larger size. I'm wondering how thick the mast section is there and what thread I should use. Does anyone have an opinion? Is it better to use a fine thread or a coarser one in this application given that I disassemble it each year.
> 
> T. Scott Thompson
> Catalina 320 "Surprise," #653 (1999)
> surprise at thompson87.com<mailto:surprise at thompson87.com>
>