Mast Base Rivet Holes Sheared

Jan 19, 2010
12,362
Hobie 16 & Rhodes 22 Skeeter Charleston
I’ve gone the re-rivet route with my mast base and have had no troubles
 
Sep 30, 2016
339
Island Packet IP 44 Ventura, CA
Here is a pic of the H23.5 mast foot that gets riveted to the mast base (top and bottom view). The right pic is the part that gets the rivets and goes into the mast.


Pic from Hunter Parts Store
 
Last edited:
Jan 19, 2010
12,362
Hobie 16 & Rhodes 22 Skeeter Charleston
Here is a pic of the H23.5 mast foot that gets riveted to the mast base (top and bottom view). The right pic is the part that gets the rivets and goes into the mast.


Pic from Hunter Parts Store
That is the exact same as mine
 
Jun 25, 2004
1,108
Corsair F24 Mk1 003 San Francisco Bay, CA
Just for clarification, the pic you posted was not a Hunter mast base, correct? O'Day?
Yup, you got that right, @CrispyCringle. It's for an ODay 192.

That's a Zspar Z145 mast foot, which was OEM on the small Oday keelboats in the 1970's. There was a thread about this a week or two ago on the ODay forum, with links to RigRite.com part numbers.
 
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Jun 8, 2004
10,024
-na -NA Anywhere USA
I have been a trailer sailor for 50 years or so.
FOR THE RECORD AND STATED IN PREVIOUS POSTS, I RESPOND TO QUESTIONS THAT PROVIDE WHAT IS NEEDED TO GIVE A RESPONSIBLE RESPONSE BASED ON KNOWLEDGE AND EXPERIENCE GAINED THRU WORKING ON BOATS PERSONALLY AND AS A DEALER, REPRESENTING MANY LINES AND SO FORTH. In addition, I became friends with many in my industry over the years being given valuable information.
First replacing, cutting or repairing a mast or part of it requires photos and without that I am not going to give a response until that happens. O'Day closed it's doors in 1989 but there were remaining hulls to be sold after closing of the plant as remaining inventory as I saw a small O'Day come thru my yard in the 1990's as either a 1990 or 1991 I think. Therefore, I am responding back to @GSBNY thinking this is an O'Day thinking this boat is about 30 years old or more.

So often I see folks saying cut the mast as a solution. It is a case by case as to the direction of what I would suggest and I will not comment until all the requested information is available. Why? First many do not have the equipment and in some cases the know how to cut a mast true and square. If that does not occur will cause the base of the mast to be lopsided putting stress on a pop rivet or screw. This also includes bolt holes in the mast as well putting stress on the bolt holes which are awkward. I have seen where holes enlargened or wallowed out sometimes causing metal fatigue even with cracks in the mast elongating and so on. Cut masts that the cut was not clean and lopsided not seating perfectly as well causing a cracks in the base of the mast sometimes elongating and so on affecting at times standing rigging. There is more but you hopefully get the picture. As for stainless steel screws into the mast, remember aluminum and stainless steel are two dissimaler metals and will corrode suggesting an ounce of insulating the two such as a gasket in between them.

Anytime you do shorten the mast and in many cases the rigging is old and stretched to the point there is not much to tighten within the turnbuckles, you will have to either replace the standing rigging or shorten them putting on studs yourself and many are afraid to do that. These are the two primary reasons but there are others.

many of the older mast manufacturers are gone leaving a handful now. Parts may not be readilby available. If I were going to shorten a mast, I would add an insert that fits the space inside the mast perfectly or if there is one made to fit the mast inside. Welding, I would be cautious for a variety of reasons and one of course is the welder with experience. I recently saw a welded section on a mast which I have reservations but the weld which is holding was performed by an experienced airplane mechanic who welds aluminum for a living on airplanes. That I will be watching closely but the micky mouse rigging has to be replaced. I have seen some make an elongated foot for the mast made out of Delrin that was made perfectly to fit the interior of the mast and worked. Anything short of a perfect match will stress the mast which it is attached to causing problems. It would take a book to write the amount of screw ups seen by me over the years.

When anything is suggested, I would also say to those proposing to supply photos as well to see if the fix worked. The old saying a picture is worth a thousand words. Again, this issue of the base of the mast is a case by case and without photos, I will not respond till then.

@DrJudyB Thank you for advising that. That is an earlier Z Spar part pointed out by you.. Kenyon Isomat was purchased by Z Spar in the 1990's with all employees for both companies let go. Only four from Z Spar went to Charlotte, NC as the only work force. I had Hunters without masts sitting for a while paying interests on them to the banks until Selden Masts came to the rescue. Z Spar left the country but remerged as US Spars later in the same location just outside Gainesville, FL. Parts for Z Spar may be obtained from US Spars but better by the forum store for the Hunters. As for the employees, Kenyon Isomat emerged as Charleston Spar and later as Sparcraft. Parts for Keyon Isomat can be obtained from Rig Rite. Friends of mine included managers at Z Spar and Kenyon Isomat.

Dave
 
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GSBNY

.
May 9, 2019
138
O’Day 192 New York
I have been a trailer sailor for 50 years or so.
FOR THE RECORD AND STATED IN PREVIOUS POSTS, I RESPOND TO QUESTIONS THAT PROVIDE WHAT IS NEEDED TO GIVE A RESPONSIBLE RESPONSE BASED ON KNOWLEDGE AND EXPERIENCE GAINED THRU WORKING ON BOATS PERSONALLY AND AS A DEALER, REPRESENTING MANY LINES AND SO FORTH. In addition, I became friends with many in my industry over the years being given valuable information.
First replacing, cutting or repairing a mast or part of it requires photos and without that I am not going to give a response until that happens. O'Day closed it's doors in 1989 but there were remaining hulls to be sold after closing of the plant as remaining inventory as I saw a small O'Day come thru my yard in the 1990's as either a 1990 or 1991 I think. Therefore, I am responding back to @GSBNY thinking this is an O'Day thinking this boat is about 30 years old or more.

So often I see folks saying cut the mast as a solution. It is a case by case as to the direction of what I would suggest and I will not comment until all the requested information is available. Why? First many do not have the equipment and in some cases the know how to cut a mast true and square. If that does not occur will cause the base of the mast to be lopsided putting stress on a pop rivet or screw. This also includes bolt holes in the mast as well putting stress on the bolt holes which are awkward. I have seen where holes enlargened or wallowed out sometimes causing metal fatigue even with cracks in the mast elongating and so on. Cut masts that the cut was not clean and lopsided not seating perfectly as well causing a cracks in the base of the mast sometimes elongating and so on affecting at times standing rigging. There is more but you hopefully get the picture. As for stainless steel screws into the mast, remember aluminum and stainless steel are two dissimaler metals and will corrode suggesting an ounce of insulating the two such as a gasket in between them.

Anytime you do shorten the mast and in many cases the rigging is old and stretched to the point there is not much to tighten within the turnbuckles, you will have to either replace the standing rigging or shorten them putting on studs yourself and many are afraid to do that. These are the two primary reasons but there are others.

many of the older mast manufacturers are gone leaving a handful now. Parts may not be readilby available. If I were going to shorten a mast, I would add an insert that fits the space inside the mast perfectly or if there is one made to fit the mast inside. Welding, I would be cautious for a variety of reasons and one of course is the welder with experience. I recently saw a welded section on a mast which I have reservations but the weld which is holding was performed by an experienced airplane mechanic who welds aluminum for a living on airplanes. That I will be watching closely but the micky mouse rigging has to be replaced. I have seen some make an elongated foot for the mast made out of Delrin that was made perfectly to fit the interior of the mast and worked. Anything short of a perfect match will stress the mast which it is attached to causing problems. It would take a book to write the amount of screw ups seen by me over the years.

When anything is suggested, I would also say to those proposing to supply photos as well to see if the fix worked. The old saying a picture is worth a thousand words. Again, this issue of the base of the mast is a case by case and without photos, I will not respond till then.

@DrJudyB Thank you for advising that. That is an earlier Z Spar part pointed out by you.. Kenyon Isomat was purchased by Z Spar in the 1990's with all employees for both companies let go. Only four from Z Spar went to Charlotte, NC as the only work force. I had Hunters without masts sitting for a while paying interests on them to the banks until Selden Masts came to the rescue. Z Spar left the country but remerged as US Spars later in the same location just outside Gainesville, FL. Parts for Z Spar may be obtained from US Spars but better by the forum store for the Hunters. As for the employees, Kenyon Isomat emerged as Charleston Spar and later as Sparcraft. Parts for Keyon Isomat can be obtained from Rig Rite. Friends of mine included managers at Z Spar and Kenyon Isomat.

Dave

Please no offense, but I wasn’t asking a question or looking for help. I made a suggestion to the person who started the thread. I’ve been in the sailing industry for over 15 years and counting and the other person helping me also spent a lot of time in the industry and is an experienced engineer who also sails (and currently owns a Flicka 20). We came to this decision after considering a range of options.

For my application, the spacer below the hinge will work fine. The mast will be properly supported by the original Z Spar casting. 1” off the mast and 1” added below the hinge will keep the rig specs right where they were and give me better clearance over my companionway hatch when raising / lowering the mast. Not saying it’s the right move 100% of the time but it’s a valid fix in my case and I believe it could be an option worth consideration for the original poster as well if they have the ability to do it.

I cut the mast today and the base will be reattached tomorrow as long as it’s not raining.

FYI:
This is the Z Spar Mast from a 1988 O’Day 192

79517C05-B93D-40B9-88F4-132656F548B1.jpeg
 
Mar 20, 2016
594
Beneteau 351 WYC Whitby
I have had a spreader welded ,and have sent 4 other people that have had their masts welded. You just need to find the right company with the right equipment. Welding anodized must be done at high frequency 400hz most shops tig welders are at 60 hz and cannot do it with good results. Bump welding google it
 
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GSBNY

.
May 9, 2019
138
O’Day 192 New York
GSBNY, thats a clean cut. Mind sharing how you did it?
Thanks, it’s always slightly nerve wracking to put a saw to a mast.

So, I waited to cut until my 1” thick spacer arrived so I could confirm that it was actually 1”. Then we used a caliper to measure the spacer and transferred it to the mast. My dad had the great idea to put a hoseclamp around the mast as a cut guide. I decided to use a hacksaw to make the cut since it would be easy to control. I cut it slow and kept checking. I filed it a bit to remove burrs and touched it up with a bit of light grit sandpaper. In the end the mast was dead flush with the hoseclamp, 1” shorter.

Here’s what came off:

68BC414F-D4AE-46B7-B7AE-BD7C01DDABC6.jpeg


F1D662F9-3785-425F-896B-7C573E92BDDF.jpeg
 

DJN51

.
Oct 26, 2009
377
Hunter 23.5 East Chicago In
Dave agree about stainless in aluminum ,used heavy plastic washer in between,check every time trailer home (slip boat),so far no problems and screws have remained tight.
 
Dec 31, 2016
319
Beneteau Oceanis 351 Charlottetown
A welders wrap-around works great for marking something like this, only about 10 bucks.
 
Dec 31, 2016
319
Beneteau Oceanis 351 Charlottetown
Dave agree about stainless in aluminum ,used heavy plastic washer in between,check every time trailer home (slip boat),so far no problems and screws have remained tight.
Thanks, it’s always slightly nerve wracking to put a saw to a mast.

So, I waited to cut until my 1” thick spacer arrived so I could confirm that it was actually 1”. Then we used a caliper to measure the spacer and transferred it to the mast. My dad had the great idea to put a hoseclamp around the mast as a cut guide. I decided to use a hacksaw to make the cut since it would be easy to control. I cut it slow and kept checking. I filed it a bit to remove burrs and touched it up with a bit of light grit sandpaper. In the end the mast was dead flush with the hoseclamp, 1” shorter.

Here’s what came off:

View attachment 167472

Nice cut! I wouldn't worry about the nay-sayers on this , the bottom of the mast doesn't need to do the flex like the rest of it does, once your shrouds are adjusted you should be good for many years. As far as the stainless screws and plastic washers, you can't get away from interaction corrosion, as the threads still make contact with the aluminum.

View attachment 167473
 
Jun 8, 2004
10,024
-na -NA Anywhere USA
@GSBNY

First, that cut was PROFESSIONALLY cut and I too concur with others and thank you to all who said the same thing and to the one about welding which the right equipment is needed welding aluminum.

When I ask for information, I do not know whom I am dealing with as to experience, knowledge, limitations, etc plus I would prefer giving a response when I feel I have enough information to do so. So, no one should ever take offense in the gathering of information. I was glad you did advise plus seeking help from others which greatly helps. I was trained many years ago as an investigator and before making a decision, all facts from all sides were obtained. In your case I would suggest cutting the mast and you thought ahead of the difference of the standing rigging without that block. I have seen many who did not think ahead like you did.

Since you are on the right approach with the I assume Delrin block material, May I assume the mast step will go on top which to attach the mast foot to? In addition, I am assuming the base or top deck which to attach that block to is flat? Thank you very much. You have no idea others are listening to you as well and we all look forward to future insight from you @GSBNY
 

GSBNY

.
May 9, 2019
138
O’Day 192 New York
So I took the 1” spacer and drilled it on the drill press today. The holes on the bottom of the spacer were countersunk so there was a recess for the butyl tape to set in. I also had to get new hardware to install the higher step, so I got some 3” x 1/4” stainless bolts.

FYI: This spacer is 1” King Starboard.

DAF6BD64-EB0C-48CE-BD19-5A60A22E8BCD.jpeg


671D9EC3-3A18-4E2E-832A-D29458FDCA59.jpeg


And once that was installed, we were able to raise the mast for the first time in over a month. Of course it started raining when I started stepping it but no lightning so up it went in the dark.

A567A575-6ECA-491D-8D13-55AE0768FE03.jpeg


The math worked out perfectly and the shrouds all tightened in their normal range. Plus, the extra 1” under the hinge allowed the gooseneck to clear the companionway better.

Everything will settle tonight and tomorrow I’ll go do some final tweaking.
 
Nov 13, 2011
163
Oday 23 New River Az
I have had a spreader welded ,and have sent 4 other people that have had their masts welded. You just need to find the right company with the right equipment. Welding anodized must be done at high frequency 400hz most shops tig welders are at 60 hz and cannot do it with good results. Bump welding google it

The problem with welding on the mast isnt the welding of anodized, anyone who can weld aluminum professionally can do it. The problem is the the mast is likely in at least a T-6 condition of hardness. 1 being dead soft and 10 being as hard as it can get. The welding anneals the aluminum in the heat affected zone down to a T-1 condition, so what was hard is now soft.
 
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