INVESTIGATOR 563

As I mentioned on David’s thread we managed to crack the original mast plug fitting when raising the mast during refurbishment. Can’t really complain after 40 years I guess. I have no idea if it was treated with anything back then but the bloody thing was glued in like no tomorrow. I managed to get one of the three screws out neat , the second needed a wider slot cut to accommodate an impact driver but the third basket wasn’t budging. I tried liberal application of heat but was scared of damaging the new wiring and spectra halyard in close proximity to the disaster area. Finally ground the head off, gingerly tried to centre punch the ss bolt and drilled out the remaining bit of bolt with a cobalt drill. Major league PITA.

Then the real fun began the plug itself was stuck solid and after bashing on the flange with a rubber mallet and soft drift nothing gave other than a section of the flange parting company. In the end we gave up and had a nice red over lunch and read my usual goto in these circumstances, Practical Boat Owner Forum . I was very concerned about damaging the mast itself

There is usually some ray of hope researching PBO but all we got was tales of doom and gloom of cutting the mast base off and shortening all the standing rigging .§€$&&@* and #$&*a. May just finish the rest of the bottle of red and forget the whole thing

After lunch we began a process of trying to reduce the mass of the plug by drilling, hacksaw and colourful language plus everything I knew about penetrating oils , heat and sweat . Nothing , nada, b*ugger all, even after we got a clean cut through the back of the plug with minimal effect on the mast tube.
In the end the thing that saved us was that flange on the plug was 1mm proud of the end of the mast (see pic ) so by getting a pound hammer and slugging it further into the mast just that 1mm we managed to break the bond of the corrosion. Bashed it back and forth a few times and finally it come out. Then finished the bottle of red
Interesting the new one, which I had on hand from when I replaced the base mount, fitted easily with plenty of play. We did however coat it with copious amounts of Duralac to save the next poor basket the same issue. Rather than thread the plug as the previous installer had done I drilled the holes out slightly in the mast and used 8 gauge ss and nylocs.

I can tell you I treated the new mast plug like a bloody Faberge Egg till I had it drilled out and installed
Just a WARNING re Duralac. I was advised by Bob Keely that it’s important to use it even between aluminium to aluminium let alone dissimilar metals and it is good gear to prevent the issues I’ve just encountered but as I’ve mentioned before it is HIGHLY CARCINOGENIC and even the dude at the boat shop when I bought it said to wear good chemical resistant gloves when you use it. After application I left everything to dry for a day, even the tools I’d gotten it on . Just sayin’ . .

Haha sorry about my Schadenfreude Ozzie but a very entertaining story and glad to hear I’m not the only butcher bird around here. You got there in the end full marks for perseverance. I find I have to use white wine or Jameson as red gives me gout these days. Yes 40 years life span amazing. I replaced mine about 10 years ago supplied by the equally amazing Bob Keely marine (saviours of investigators).
I broke my mast step and the foot learning to raise and lower the mast. I wince watching mast raising youtubes. ( more Schadenfreude) You can see their masts at crazy sideways angles putting huge pressure on the mast foot. The Aldi ladder and double pulley system I copied did the trick for me. Here somewhere on this site.
Thanks also for the Duralac warning. Still lots of nasties in use out there.

Can never stress it enough David. We have lived with chemicals for so long they have become invisible. Some small print warning on cans just doesn’t cut it IMHO. Humans have a long history of failure with chemicals, DDT, organophosphates and locally the current uproar regarding fire fighting chemical residues from our RAAF Base at Williamtown which have contaminated the water table for hundreds of square kilometres. Bad all round.

Hi Emrys, red is one chemical I can luckily still enjoy when the mast fitting would not budge I consoled myself that at least it would make a good post

Just found another pic from this saga that I had forgotten about. When I used the pound hammer to belt the plug further in, the mast fitting for the spinnaker pole simply fell off closer inspection showed that like the masthead light the pop rivets had turned to talcum powder. Marvellous. More wire brush work and lashings of Duralac. This was getting to be a habit. Warning Warning Will Robinson , check ya rivets

Sage advice David and makes good sense. Not much point having perfectly good ss rivets in the mast if a huge hole has corroded in the mast tube itself. It’s a good example of what you say in that when we ultimately separated the plug from the mast the interior of the mast tube was in very good condition but the softer cast plug was quite degraded and that had created the bond. I’m learning every day. I actually use a fairly fine ss brush about the size of a toothbrush from the reject shop that come in a package of three, one bristle, one ss and one brass I think. Cheap as but handy, particularly for electric contacts. The fibres are fairly fine and soft so hopefully I didn’t do too much damage but I’ll be aware of this in future

The advice I have been given on rivets in aluminium masts is not to use stainless at all, always use monel rivets. This advice came from Mitch Ranson , who builds and works on masts as a profession. His business is called " Allmasts Australia".
Stainless is probably the worst for creating corrosion that could be used

It’s amazing how we take aluminium for granted these days. Once it was rare. The feature article on Wikipedia earlier this week was on the Washington Monument. Which has an aluminium top piece. Anyway for those interested....

“The aluminum apex, composed of a metal that at the time was as rare and valuable as silver, was cast by William Frishmuth of Philadelphia. At the time of casting, it was the largest piece of aluminum in the world. Before the installation, it was put on public display at Tiffany's in New York City and stepped over by visitors who could say they had "stepped over the top of the Washington Monument". It was 8.9 inches (23 cm) tall before 3⁄8 inch (1 cm) was vaporized from its tip by lightning strikes during 1885–1934, “ you can wow people at your next BBQ with this stuff.... or not

By the way aluminum (no second i) was popularised by its use as brand name for its production but the US adopted it as the metals name. Likewise Canada.