Mast Boot

[Bud Cary]

I’d be interested in what anyone has found works best to secure the mast where it goes thru through the deck and what to use as a sealant or mast boot to prevent water intrusion

 

I inherited a mast collar on my relatively new to me J40 that was not holding in place, so I wrapped two pipe bands over some L brackets to hold it down. This seems to work decently well, but would like to hear if anyone has done something different

 

The second issue is keeping water from dripping down into the cabin. I wrapped the mast and the collar with Rubbaweld tape and put tape over any other possible nearby point of ingress, but had much less success. After a heavy rain the forward head shower sump fills with water. I removed the Rubbaweld wrap and found a lot of water around and on top of the collar, so looks like the Rubbaweld’s not doing the job. Either I didn't wrap it well enough or next option would be to try adding a mast boot, but wanted to see if anyone has found a better way before I go down that path

 

Apologies for the mess in the picture … hadn’t cleaned up what came out from under the tape after removing it

 

Many Thanks

 

Bud

 

J40 (#82) S/V  Pooh 

 

 

 

 

[Michael Kahn]

Bud,

I’d recommend Spartite. We did this upgrade in the offseason and have found it to work very well with no water intrusion on our J-40. Hope this helps. 

Michael

On Sep 4, 2025, at 17:07, Bud Cary <afca...@gmail.com> wrote:



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[Rod Deyo]

Spartite and self-amalgamating mast boot tape.

Rod Deyo

J/42 Northern Lights (#61)

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Rod Deyo

[S/V Sweet Ruca]

I would second this. Adding a light bead of silicone around the spartite to mast and spartite to base connectuon has also served well. 

Like Rod said, cover it all with mast boot tape. 

Only a few drops have ever made it in (likely from the instrument wire hole or halyard holes).

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[Paul Rogers]

The water you are seeing in the sump is coming down inside the mast.  If you leave the boat for a long time in rainy conditions, detach the sump hose at the main cabin bulkhead so the rain water will drain into the bilge. Otherwise the water may overflow from the head and ruin your forward cabin deck.

Paul Rogers

J42 #38 Canty.

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[David Jade]

We added one of these clamps as well. It really helps adhere the boot as the mast has a bit of an irregular shape right where you’d want to seal it (on the J/46 mast at least).

 

We have zero leaks around the mast now.

 

We got our from a rigger near Annapolis but if you search Amazon, they appear to be ‘stainless CV boot clamps”. The one we have required no special tools to put it on. Just cut to size and it works like a regular band clamp more or less – just bigger.

 

Also, we greased the Spartite for easier future mast removal - it’s a pain when they stick. The grease probably helps with the water sealing as well.

 

David             _/)

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[Bud Cary]

Thanks to everyone for the recommendations and comments .. will look at doing Spartite  … I assume one of the challenges is to ensure the mast is properly positioned and stable while making the mold

 

If some water is also coming down inside the mast, and I would think there is, we are fortunate we are docked in a canal outside our back door (SW Florida, hence the heavy summer rains) so at least can check and run the sump pump anytime or as suggested just let it drain to the bilge

 

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[Ed Sitver]

The only bit I have to add is to recommend the mast boot I use over my spartite. This is the mast boot solution that I found works extremely well: https://waterboot.com

As mentioned by others, some rain water will come down inside the mast, so when not on the boat for an extended period of time, I also let that drain to the bilge, but I don’t see any water intrusion between the collar and spartite with the Water Boot. 

It’s just a stretchy rubber that I’m sure one could find on McMaster, but the path of least resistance was to purchase it from the vendor, already cut and with velcro installed. It gets stretched around the mast and collar, and velcro holds the “seam” while tape is applied top and bottom (I use white electrical tape), and a bead of silicone or other pliable sealant is applied to the seam with the velcro to guard against water seeping in there. 

Ed

[Rod Deyo]

After you do the Spartite, it's a good idea to drill and tap the mast collar for set screws forward and aft to keep the mast bend from slowly lifting out the Spartite.

Rod Deyo

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[ankg...@gmail.com]

J/Boat Fans,

 

I’m considering putting my 2002 J/46 Hamburg II on the market and wanted to give y’all the opportunity to jump in before she goes to a broker. If you’re seriously interested, please drop me an email to my personal email address and I’ll get you more detailed information. I’m the second owner and have enjoyed here for the past 11 years. A few key features:

 

This is the racing oriented version of the boat with the deep keel (7’-6” draft) and extra set of mid-ships winches. She has an extensive (and current) set of carbon racing sails as well as a set of (rarely used) cruising sails and storm jib/trysail. Pretty much everything has been upgraded in the last few years. B&G H5000 instruments, autopilot, ram, recent new standing rigging, all running rigging is low stretch dyneema or equivalent. The boat has a recent racing bottom and awlgripped hull sides (vivid red) in 2022. A few years ago I had the keel removed to inspect the keel bolts – they were perfect. The boat has a diesel heater and air conditioning, but no generator – for weight savings.

 

When I bought the boat in 2014 I had the entire deck stripped of every single attachment and the crazed gelcoat ground back to the glass and re-gelcoated. There is very little of the crazing that was so common on boats of that age. The non-skid is ~2 years old.

 

I’ve attached a few recent pictures. Drop me an email if you’re seriously interested!

 

Al Goethe

[Chris Leo]

Brings me back to the first time my boat nearly sunk....while on land in winter storage in Jamestown RI. Not aware of problems with mast boot (or even what one was) a couple months after purchasing her I dropped her off to be shrink-wrapped, and came back in the spring to 6 inches of freshwater on the sole. A bit of cosmetic damage mostly to the teak but a real lesson in making sure your mast boot is secure! Especially if disconnecting the batteries and turning off all systems. 

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[David Tabor]

I HIGHLY recommend this step.   Coming back from Bermuda, our Spartite lift out and I kept having to go forward with my deadblow hammer and pound it back in...  Then when I was at the wheel for 14 hours straight in squalls in the GS it did come out all the way.  My wife said water was pouring in and the mast was moving side to side.  She did jam some rags inside of a plastic bag in there to slow down the ingress.  Was not a night I want to repeat ever.  Needless to say, there are now three screws securing the Spartite.

[Bud Cary]

The collar around my mast also lifted out. What was recommended to me was to put a brace above the collar held tightly in place to the mast by two stainless steel hose clamps.  Over top that is a mast boot

 

Bud Cary

S/V Pooh, J40

 

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[Joe Murli]

I used 3” wide rigging tape and replace it every year. I find the boots sont work very well

Joe 

“Sirena Bella II” 

Sent from my iPhone

On Sep 4, 2025, at 5:26 PM, Rod Deyo <roder...@gmail.com> wrote:



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[York.richardw]

I had a difficult time keeping the mast from dripping at the partners even with Spartite properly installed (3 tries over 1.5 years).  Part of the reason is the shape of the J/46 stick there with several dimples, especially under the vang support.  

To be short, the solution that works for me:

1. Spartite, assuring you have 2 ser screws holding it in place.

2. A hose clamp just above the Spartite to further keep it in place. 

3.  The secret weapon is roofer’s rubber, sticky bottomed membrane (comes in widths of 6 to 9 inch.). I roll this carefully around the mast partner and the mast.  I think I put a second roll above the first as the first gets puckers where the diameter steps down.  If you do this carefully, you solve 95% of the problem.

4.  I still use (an adhesive) electrical tape or similar in tactical locations where folds in the tape or dimples in the mast may allow water in.

5.  If you don’t like the (slightly ugly) look, cover with self-amalgamating mast boot, again using tape in critical locations so no water gets behind it.  This layer  will deteriorate over the year, so be prepared to replace that before real leaks arise.

Done well, you can cross the Gulf Stream without water coming in (at the mast step).

Thank You … Dick J/46 #9, ARAGORN 

On Jan 28, 2026, at 20:03, Joe Murli <mysticpu...@gmail.com> wrote:

I used 3” wide rigging tape and replace it every year. I find the boots sont work very well

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[Paul Rogers]

Thealuminum mast on the J42  gets a ton of rain water down the mast.  In 2004 I left my boat covered in Scotland with the mast in.  When I returned in the spring, the rain water had overflowed from the head to the forward cabin destroying the cabin deck.  The solution is to disconnect the head sump hose at the main cabin bulkhead and let the water drain into the bilge.

Paul Rogers

Canty J42 #38

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[John Plominski]

I will second many of the comments here and add a few things:  

1. Spartite is well worth the effort.  A couple tips on doing it:  Pay a professional, it can make a HUGE mess and stain the deck (or find a friend who has done it a few times, it makes a difference).  If not:
   • Use a small set of tackle clipped to the toe rail to get the mast centered in the partners before you pour.
     • Re-center and check your mast for straightness and even rig tension if you had to manipulate the mast for pouring.
   • Be LIBERAL with the vaseline for where you want it to release, like the inside of the partners.
   • Drill and tap a couple set screws to keep it from working out of the partners.
   • Put the sticker they provide which warns riggers and reminds owners you need to remove those set screws before pulling the rig!
2.   Self sticking mast boot tape is amazing, cheap, and a no brainer.  Very similar to self adhering rigging tape but much wider.  $32 on amazon, delivered to Boston, MA tomorrow:  Mast Boot Tape on Amazon  Put a large hose clamp or wrap tightly (or both) electrical tape around the base to make sure it stays attached to the stainless collar at the partners.
3. Find that lower section of the mast track above the vang and where the mast boot tape crosses the track and pump a couple inches along the track near the partners with bathroom silicone sealant to stop the water from coming down that way.  You'll always have some rain water coming in from higher up openings in the mast but this keeps the bulk of rain and greenwater out of the forward head.

Drew

J40 #78