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kgilbert
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Mounting T-Track on the mast

I'm going up to the boat next Saturday to install a 1-1/4" t-track on the mast. I got a Forespar whisker pole and am going to store it on the mast. Can anyone tell me what type of screws to get to screw the t-track to the mast? I've never attached anything to the mast extrustion before, and it makes me nervous. I assume self-tapping stainless screws? What length? Once I'm up there there aren't any supplies for 300 miles, so I need to bring the correct screws with me. Thanks for any advice anyone has.

Avalon
1996 Catalina 36 MKII
Lake Superior

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GaryB
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Years ago the boatyard I used actually set me up with a tap drill, tap, and anti corrision compund to mount a new fitting to the boom. I just used short SS machine screws. No matter how you do it self tapping screws etc., you will need to use a anti corrision so you can remove at a later date should it be required. Another option would be using a SS rivet.

kgilbert
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Thank you Gary. I hadn't thought about anti-corrosion compound...good advice.

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Ray Taylor
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I’m in the process of mounting a mast track right now.   Others who have completed the job on a Catalina 36 are better qualified to offer advice.  That said, I’ve used the following method on other boats and it worked well.

In my case I’m mounting a 6’ Schaefer 1 1/4” track to the front of our mast.   I’m using 5/16” x 18 x 3/4”  bevel headed screws.  The whisker pole is mounted on our stantions.

The process goes something like this:

Determine the location of track.  Both up/down and square to the front of the mast.   Hold the track in place with masking tape.  

Start at the top or bottom carefully center punch the mounting hole in the track end.  Drill the proper size hole for the 5/16” screw then tap the threads.  A little tapping lubricant will make the job cleaner and easier.  Note that I made a bushing for my center punch that helps center the punch mark.   

As Gary said use some type of corrosion paste on the screw.  This will minimize corrosion between the aluminum and stainless.  I’m using TefGel but there are many other good options. 

Once you get the first screw in work toward the other end.    One screw at a time.    Much of this work will be done well above the deck.

Mast mounting the pole requires a longer track, method to hoist and lower the car, and whisker pole end that will pivot 90 deg.     Well worth the effort.

Many use a combination drill/tap for this work as Gary indicated.  I’m using a dedicated drill and tap.  Mostly because I already have a new set and they do a little better job.  If I was doing a long track, suspended from the halyard I’d take the good advice and use a new drill tap combination.   

Good luck with your project

kgilbert
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Thank you Ray for the detailed advice. I appreciate it. Why is it necessary to tap the threads? I would think aluminum would be soft enough I could use selt-tapping screws. But I assume you tap the threads for a reason. I'm new to this.

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Ray Taylor
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I think you could use several fasteners to mount the track and I even read that someone used pop rivets.

In my case I first installed a spinnaker track on a race boat in the early 80’s.  Asking around, everyone suggested machine screws so that’s what I used.  We put lots of hard miles on that boat and never had a problem.   I can't think of any reason a self tacking screw would not work, but based on my past experience I decided to go with what I'm confident in.

 

 

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Clifford Bassett
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Remember when drilling on the front of the mast that the wiring duct is attached inside.  Also use fine thread screws not standard thread. The aluminum mast section is very thin, and the fine thread will give you more threads.

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LeslieTroyer
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Cliff
that runs counter to all I've read. 
 

Coarse threads in aluminum are considered stronger, fine threads are considered stronger in harder materials. Coarse threads in aluminum are considered stronger, fine threads are considered stronger in harder materials.

more threads doesn't mean stronger.   In soft metals the course threads give more gap so the metal has to work harder to pull out.  Also more threads give you more stress points to fail.   

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Chachere
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I've had the installation of a track for the whisker pole on the wish-list for several years, and Cliff raises a concern I've had, which is "where exactly is the wiring conduit located"?  Having never pulled the mast, I just don't know. I wouldn't want to inadvertantly drill into that and damage the wires.   Does anyone have a sketch or photo?

I won't opine on the coarse v. fine issue.   I have drilled and tapped several times into our mast to add various things (small cleats, rope clutches, and a winch) with no particular issues (used anti-seize on all the threads), and I can't recall which type of screw I used.   My only advice is to take it slow, use plenty of oil, and don't overstress the tap (not fun if it breaks off inside the mast with a partially-tapped hole).

 

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LeslieTroyer
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Matthew

you can tell where the conduit is by the long row of pop rivets going up the mast. (Don't know if in mast furler are different)

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Ray Taylor
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Yep.    The PVC pipe/conduit is opened up allowing access for the motor/deck light combo near the spreaders.   This keeps the bulk of the wires out of the way for this job, but not all.  My boat has radar and mast head transducer wiring outside the conduit along with the halyards. 

It’s always a good idea to limit how deeply your drill bit enters the mast.   Some use a drill stop or just masking tape to indicate the depth. 
Also no idea about in mast furling

.

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Clifford Bassett
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Hi Les,

I wrote a reply to your response to my comments on Fine Threads vs Coarse Threads.

No Rush
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Bring extra  good quality drill bits, your bound to break some.

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Pgutierrez
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I did this project last year with a 60" track.  Buy a set of drill stop collars to prevent your drills from going in more than 3/8" into the mast and avoid pinching into halyards or wires.  I think (wish) I had bought the combination drill tap.  Didn't break any screws.  What is difficult is to perfectly drill & tap so you are dead on center.  If you are off a tiny amount, say your drill rolled out of the center punch point or the beveled screw head goes in at a slight angle, the movable track clip might not move perfectly up / down the track as it can either catch on a slightly high edge on the screw or you have slightly torqued the rail off of straight because your drill tap rolled off dead center.  Just saying I did this at the end of the season last year and now have to go back and see why my clip catches on the track....maybe should have used a shorter track length.  In hind sight, for a long track, what I should have done was to divide the drilling / tapping project in two (top half / bottom half) and alternate one screw on top, one on the bottom, then one in the middle and repeat the process (top half, bottom half.  Hard to explain - do the top screw first, the screw at the bottom of the track next, then the mid track screw, then check to make sure the clip slides with out catching, then repeat the drilling pattern on the top half of the track

two-rocks
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Just did this. Pole storage on the mast is fantastic.

use a GRERNLEE drill/tap in an impact driver. Takes seconds to do each hole, add Tef-gel and off you go.  The drill/tap is an amazing invention - more so considering you'll be hoisted up the mast. Skip all the extra drill bits and other doohickey stuff. Greenlee drill tap (period!).

The cheek blocks and other hardware I used a traditional drill and tap - while easy in aluminum, and only a few holes compared to the t-track- you will miss the drill tap!

some other points - put the cheek blocks just before the end of the track- no chance of breaking the plastic end cap under load - if you need the last couple of inches of track you can just lift as needed - and offset the block to facilitate this as well. I used the shaefer t-track and skipped some of the fasteners in the upper area as the forces there are minimal. 

make the track high enough to get the pole over your dinghy if you store it on deck when offshore - otherwise you'll  be on passage and not able to use the pole. Once you use the pole you wonder why you didn't get one sooner ;-)

kgilbert
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Thank you everyone for your sound advice on this project. It really helped! I sucessfully mounted the track this weekend. A couple of notes that might be helpful for future readers of this thread: 

1. I used 1/4" x 3/4" machne screws, instead of the recommended 5/16" x 3/4" screws. This seems to me to be plenty strong (there are 30 screws in my 10' track!), but since the heads are smaller there is no problem with a crooked screw obstructing the car that slides on the track.

2. I used WD-40 as a tap lube. Just dipped the drill bit in a paper cup of lub before drilling/tapping each hole.

2. The job was much messier than I anticipated. No good way to contain the surprising quantity of aluminum shavings from drilling, combined with the mess of using anti-seize compound on short screws.

kgilbert
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One more question: Is there any reason why I can't use my Spinnaker halyard for the topping lift for the whisker pole? I read somewhere about a downside to this, but I can't seem to find the source and can't recall what the downside was.

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LeslieTroyer
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The only drawback to using spin halyard is it will chafe on the forestay as the block is fwd of the mast. 

your bettter off using spare jib halyard.  

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Ray Taylor
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Good to hear that your job went well.  

IMHO  there is no reason you cannot use the spin halyard as the pole lift.  

On our Catalina 28 we sailed 100’s of miles with no pole topping lift at all.  Just hooked the pole outboard end into the clew ring of the headsail.  As time went on I made a small Dyneema loop tethered to the tack, making it easier to  catch with the pole.   I realize this is unorthodox but it worked fine. 

This would be a disaster with a symmetrical spinnaker but it worked with headsails and our gennaker.    

 

We had a big weekend too.  Mounted and ran a spinnaker halyard, mast head rigging inspection, re-wrapped, inspected the spreader tips, and finished the mast track.   Hardest part of the whole job was cleaning the aluminum chips from the non slip.   

I attached a photo of the tools I used for the track job.   Next time I’ll include a shop vac to minimize the drilling mess

.

 

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Clifford Bassett
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This is in response to Les's comments on " Fine Threads vs Coarse Threads."  Here are the facts :  1. Fine threads are better for tapping thin walled members because tapping torque is lower for the short engagement length.  2. Fine threads are stronger for fastener sizes one (1) inch diameter and smaller, gaining strength as size decreases.  3. Where the length of engagement is limited, fine threads provide greater strength.  4. Fine threads are stronger in both tension and shear due to having a slightly larger tensil stress area and minor diameter.  5. Fine thread screws have less of a tendency to loosen under vibration due to their having a smaller helix angle than coarse threads.  

The secret to tapping into soft material is to use a slightly smaller drill size than is recommended in most drill size charts.

I just thought I should clarify this subject.

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LeslieTroyer
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Cliff I guess we'll have at agree to disagree.  A quick search of "fine vs coarse thread in aluminum" overwhelming favors course.  

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Clifford Bassett
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Les,

Not sure how you can say overwhelmingly favore coarse thread.  

Fine Threads are much preferred in soft material such as aluminum, plus all the other reasons I listed above.

Aerospace applications generally use Fine Thread Fasteners due to their increased strength.

You are just wrong.

Not sure of your education level but I have a Bachelor Science Degree in Mechanical Engineering

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LeslieTroyer
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Cliff.  BS in Materials (Ceramics). 

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Chachere
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You two guys (Cliff and Les) keep this up, you're going to need to hire some of us types.
Matt (J.D.)
(uh oh, cue the lawyer jokes....)

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Clifford Bassett
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Well Les,

I know who to consult before purchasing my next " VASE."

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