Mast Base Drain Hole

I was reading in the manual that it was suggested to drill a 3/8" hole in the aft end of the mast about 1 1/2" up from the base for drainage. I expect that I am collecting water in here and would like to provide this drainage, but wanted to better understand exactly where to drill and what I will encounter inside before doing this. Just had a few questions:

• Should the hole be drilled at the aft end right in the center
• At 1 1/2" up from the base will I be drilling through the mast heel fitting or just above it into the cavity in the mast. Not sure if that is the correct term but I'm referring to the insert (assume is aluminum) that fits up inside the base of the mast.
• The other thought I had was concern over contacting the wire harness in the mast with the drill bit, but assume/hope that is coming through the heel fitting in the center and if I know how thick of material I'm drilling through I'll just put a stop on the drill bit.

Insight from someone who has done this would be appreciated.

Keeping busy with boat projects here in Michigan hoping the winter will eventually come to an end and Lake Michigan will be fluid again.

Best regards,

Mark

I have only posted a few times and thought my boat displayed in my post as part of my profile. The drain hole question above is in regards to a Commander (#94).

Thanks,

Mark

Mark, You can get a visual of the bottom of your mast by going in thru google with
the prefix: PearsonAriel.org Mast step discussions.

Look at page 5 of the thread and checkout commanderpete's photos....post 80, 81. 83.
You are looking at the MAST-BASE CASTING that anchors the Commander (and Areil) mast into the mast step.
You will notice the MAST SHOE (let's call it that, because it sits on the top of the MAST STEP
and that the mast extrusion slips over the mast shoe)
You can see the edge of the mast extrusion sits on a nice tidy 1/4"-5/16" sole (to keep the metaphor going).
The rest of the aluminum casting is inside the mast. Guess about 1 1/4" up from the 'sole'.

Would say that the mast shoe's bottom inside is about at the bottom of the mast extrusion outside.
In other words, where the mast extrusion sits on the rim, that is pretty close to the bottom of the casting's bowl shape inside the mast.
This is where water wouyld naturally collect, if the bowl didn't have a big hole in it.
That's where mast electrics drop thru the mast step and thru the deck to inside.
That hole caused a lot of troubles over the years in a number of boats because Pearson never waterproofed the
balsa core of the composite deck underneath the mast step. You might check the deck if spongy or depressed around the mast-step.


So drilling a WEEP HOLE is moot. Rain gets in thru the mast head and mast sheave up top, and the steaming light half way down.
And any other open holes that water streaming down the mast would like to dive into. Condensation probably plays a role.
A drain hole drilled into the MAST TRACK FLAT just above the cast rim (sole) would do the trick. Imco.
You can see in the photos you'll be drilling thru about 3/4" of the casting donut. Piece of cake.
Doing this makes a messy hole thru extrusion and casting.......cannot recommend doing this.

WIRE CONDUIT
Pearson passed the harness thru a piece of 3" STAND UP CONDUIT attached vertically to the mast step, into the center of the casting.
Commanders have a compression post so electrics may enter the interior differently than an Ariel.
However the conduit interface was never waterproofed. Consequently the hole leaks, getting into the deck core and boat interior.
That hole for the harness in the center of mast's footprint is at the lowest point inside the mast.
IF that piece of conduit is allowing water inside the boat there, there will never be a drop of water coming out of a hole that is 1 1/2" above the bottom of the casting..... Unless you collect 1 1/2" of water in there first.*
A 3/8" hole as recommended there might vent a wee bit of a breeze to help dry things out.

If the harness inside the mast goes thru a piece of conduit in the center of the mast, as designed,
you're not going to hit the wires with your bit. HOWEVER....
however, it is possible that the bundle has a 'drip loop'
(wire is allowed to droop below the top of the conduit, forming a loop before entering the conduit)
to make sure water doesn't follow the wire run down the hole.
You could hit wires, more likely run into a loop higher up. Can't assume anything.
Possible that over the years wires and lights have been replaced.
[If you already have that 3/8" hole in the track-flat, an inch and a half or so above the base, reach in with a dental pick, and feel around for the wires.
A loop will be fairly loose and wires going directly down the conduit probably feel tighter....]

If you want water to actually drain out the mast, imco it would be mo'betta to rout a 3/8" wide channel into the base of the casting.
Rout the channel with a core-box bit & router - straight in along the bottom from the mast-track flat side - just to the height of the exposed rim. About a 5/16" deep channel. Not likely to weaken the piece - if it's still in decent shape.
........Maybe when the mast down to replace the old wires and installing new LEDs.
Have fun!
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*By the by, it's sweet water, not salt, that causes rot.
So theoretically, you could poke rocksalt (kosher, of course) into the 3/8" hole and pickle the water so it can't support mold.......:D Too late!

Cpete gives us chapter&verse on how difficult it will be to remove the casting.

If the mast is off the boat and horizontal, and you have decided not to take the heel casting out,
Suggest building a small tight fitting plywood box sleeve around the bottom of the mast as a temporary router 'table'.
(see Ebb's gallery photos pg21 for an example.)
Use a jig like this to rout a short 1 1/2" long channel into the bottom of the mast in the cast aluminum fitting* - suggested in the previous post.
You can custom wood strips onto the jig that will snugly track the router's base so the router's torque won't pull or jump it off the work.
Just go slow and careful using a 3/8" or 1/2" core box bit. Lowering the bit a bit at a time with a number of passes.
Cut the channel toward the square tenon, and place a stop in the router track so you can't reach it. Maybe that's all needs be done....
But, after you've routed the short channel to the depth of the 'rim' AND still can't see inside the mast,
measure 1" in from the edge and drill a hole in the channel thru to the interior. This creates a drain for the mast.
Offset misses the thickness of the casting donut. Can't be much more material to drill into across the bottom there, never know.**


Maybe easier is simply to drill a tilted horizontal hole thru the RIM of the casting into the interior, also from the track side.
Estimate a slight angle upward, aiming at an imaginary point inside about 1" in from the edge.
[Obviously a tilted hole like this can't be done with the mast up.]
You want to miss the electrics hole, which will be too low an angle.
Ideal if the opening you've just drilled appears inside the casting fairly close to its thick wall, which coves with the bottom about 7/8" in from the exterior.
Still be good if the bit went thru the inside wall at the bottom of the bowl, a slightly higher angle.
Best, probably, right where the sides and bottom curve - refer to Cpete's photo 84 [P.A.org mast step discussions - archive]
It's guesstamate.

Might be more sure by first sketching a full size to scale picture of mastbase.... to generate the correct drilling angle.
Outline how you think the casting is......what is seen outside as the extrusion intercepting the rim is about the same level as the bottom of the cast bowl inside.
Smaller bits first, but smaller bits break. Secret is sharp new bits. Where you drill: first file the base back to a flat right angle to the bit.
3/16 to 5/16 to 3/8" depending on how accurate you start the drill in the base.
Cool hot bits by dipping in water or isopropyl alcohol. Don't spin the bits.....when drilling, press to remove material, then release.
You're drilling thru solid aluminum that will suddenly break-free inside at a radical angle to the material...carefull.
Messed it up? NBD, it's fixable with epoxy or Lab-Metal.

Alternately, you can drill in thru the bottom of the mast extrusion itself above the cast rim......(NOT recommended:
It can be done almost straight in horizontal.....if you have to......) Way more cool imco to drill in thru the casting rim.
You won't be creating an easy invitation for stress crack cancer, or a mangled hole at the bottom of the mast.

Attend to the electrics conduit. On A338, all stuff that has to come apart again sometime in the future is bedded in tape butyl***
(NOT putty, NOT gun grade rubber - except for the conduit piece alone, which can be permanently poly-rubbered to the step. imco..)
When you position the mast back on the step put an extra roll of butyl around the fitting
so that the glob remains higher than the bottom of the bowl. Non hardening butyl will eventually settle into the hole in the casting and seal it.
And the mast can be easily lifted off again (IF you've used no tube rubber.).......... Voila'.....no standing water in the mast.....:cool:
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* looking at Cpete's photo at post #81 in the Mast Step Discussions thread: The proposed channel is routed into the casting on the pointy side. Don't want to gouge into the tenon so you may be stopping the channel shorter than 1 1/2". The procedure assumes that the heel/shoe remains in place in the mast extrusion.
**Understand that ole Ebb hasn't actually done this procedure. A338 has a renovated, altered base with G-10 insert (for forward tilting) mast and elevated mast-step that bears no resemblance to the original Pearson factory shenanigan. Balsa core deck under the mast has also been restored.
***www.sailrite.com/Trimmable-Butyl-Tape now sells 1/16"thick 3/4"wide offwhite butyl tape (pricey) but they have a couple videos that are excellent. We've been talking about butyl tape for years. Sailrite makes it easy to get a roll! Haven't used their product, but they make it look real easy.
DISCUSSION
The drain idea is put forward for discussion....KICK IT AROUND !
This is all imco, ideas, suggestions, subversions......exercise caution!

Ebb
Hey thanks for the time to respond. With the pics you provided a clear picture of what lies beneath and a simple plan to addressing the problem when I have the mast down. If feasible when I get into it I'd like to use the angled weep hole in through the sole of the cast shoe into the collection point inside and the sealing of the conduit at the shoe penetration. Always good to have a plan before the start of a project, but looking back the final solution often deviates significantly