Standup Zone Forum

The Foil Zone => Wingsurfing, Windfoiling, Wingfoiling, Wing SUP => Topic started by: PonoBill on May 08, 2021, 04:07:44 PM

Title: Oh crap, screwed up in the last step.
Post by: PonoBill on May 08, 2021, 04:07:44 PM
I repaired my 76 CM mast over the last two days. I hammered the broken bit into place with some JB Weld buttered on every broken surface. JB weld is the vintage racer's friend, and it works as well as any thickened epoxy. then I ground the tuttle-like connector a bit with the brass drums that accept the screws in place. My plan is to wrap the connector with carbon and go right over the holes for the drums. I wanted to add as much strength as I can. So I did that--three wraps of 3K carbon twill, then two of 4OZ fiberglass as an insulation/sanding layer. Mark tells me that bare carbon in contact with aluminum will eat up the fuselage. A brief look at the electrochemical constants for carbon and aluminum tells me the fuselage would become a sacrificial anode. So I'll do what Mark recommends.

The connector was loose after all this, as I expected, but should be back to something line original strength. So I gooped up a fuselage with mold release, put a piece of thin plastic into the cavity to help release, and then added five layers of table-wet 6OZ glass to the connector--four layers wrapping horizontally and the last wrapping over the top to keep the guts in place when I put the fuselage on as a mold. I put a layer of cling film over the connector, pushed two straws sized to the bolts holes into their respective holes, and jammed the fuselage down on it.

One it kicked, the fuselage came off fairly easily. Everything was looking good, but I decided to chase the threads in the brass barrels with a 8M 1.25 tap. Worked fine on the original broken one, but the "good" one felt funny. I ran the tap in and out a few times, and it started feeling good, so I ran it deep--apparently too deep--and took the threads right out of the damned thing.

Normally this would be no big deal--punch the barrel out and replace it. But I glassed over the top of the dammed thing, and I didn't really want to compromise the strength. So I ordered some 8mm stainless steel helicoils. I think most helicoils are stainless steel to start with, but I'm not taking chances.
Title: Re: Oh crap, screwed up in the last step.
Post by: surfcowboy on May 08, 2021, 07:39:43 PM
Look, if you got that far, you made it past most folks. Are you saying you basically took the mini Tuttle down a bit and then built it back up with carbon and glass?
Title: Re: Oh crap, screwed up in the last step.
Post by: PonoBill on May 09, 2021, 10:04:21 AM
Title: Re: Oh crap, screwed up in the last step.
Post by: Wingingtanuki on May 10, 2021, 11:20:09 AM
Regardless of the last minute mistake, at least you'll get it done.

My repair would've gone like this:
1) Get resin all over my hands and transfer to every surface in my garage
2) Curse and go look for the acetone
3) Lose patience and try to get everything together quickly before it sets
4) Have all parts set at slightly the wrong angle
5) Curse some more
6) Attempt to sand away the mistakes
7) Wife comes into garage, point out mess and questions why I've been there all day
8 ) Get mad at her for pointing out the obvious
9) Leave everything and go apologize
10) Grab beer, open laptop and order new mast on internet - After all, I needed a taller one anyway.
Title: Re: Oh crap, screwed up in the last step.
Post by: PonoBill on May 10, 2021, 11:44:58 AM
Actually that all sounds familiar, except for #10--I already have a 96CM mast, I love the 96 in the Gorge, but here in Maui it's mostly useful for banging my wings into things.
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