Screw length to attach T-Track to mast

[Rosetta Stone10263]

I am attaching 1 1/4 inch aluminum t-track (12 foot section) to forward edge of mast for a whisker pole car. Screws specified are 5/16 inch flat head. I will drill/tap the holes and use tefgel. Does anyone have a guess as to length of screw needed? I don't want them protruding too far into mast for fear of interfering with internal halyards. Boat is Beneteau 440. Thanks, John.

 

[markwbird]

My guess is that the aluminum is about 1/8" thick. So that plus add a little more

 

[Richard19068]

Why guess? Maybe figure out what mast you have and then look up the specs for wall thickness. The Rig Rite website might be helpful for that.

Maybe this one?

Sparcraft F-760E Mast

www.rigrite.com

That one is 3.9mm minimum.

After you drill the holes you should be able to get a pretty good idea of the actual thickness.

 

[Hayden Watson]

I had the same concerns when I added enough track to mount my whisker pole vertically on my mast. I drilled the first hole and measured the mast section on the front edge. I then bought the shortest length would reach all the way through the mast wall. It stuck out about 1/8" beyond the inside surface. Then I used my bench grinder to grind the end of each screw to a slight burr-free rounded surface that would not snag my expensive halyards.

That was about a decade ago and so far, so good.

 

[Hello Below]

Have you considered SS rivets?

 

[shemandr]

It's a wild guess without knowing the track thickness. My wild guess is that track is 1/4" through. The mast is about 1/8" thick. So 3/8"? Maybe 1/2"?

 

[Hayden Watson]

Have you considered SS rivets?

It takes a special heavy duty compound gun to do 5/16"ø SS.

 

[jssailem]

measure twice cut/drill once.

 

[Mechone]

Personally I would use SS rivet nut inserts. Have used them for years in Industry. Like a rivet however you use a SS bolt to attach track ,is removable and much stronger then tapping aluiminum and replaceable if ever stripped ,however unlikely. Used them 3x this week alone. They are also available in Aluminum, steel etc

 

[Mechone]

It takes a special heavy duty compound gun to do 5/16"ø SS.

Yum if you can't afford one rent it