The boatyard just cut out the mast step fiberglass without making a template.
I need one if anyone has it.
Or at least measurements relative to the keel well to the SS mast step bolts, or the mast pivot slot.
Anyone got the data?
Thanks,
Ron
PS -Alas, the joys of a newbie....
Mast Step Measurements or Template
Moderators: Tim Bosma, Tom Elsen
Re: Mast Step Measurements or Template
Dear Ron -
Some folks here at the Sandusky Sailing Club may have a mast step template for you, or at least some measurments for it. Do you still need that info?
AJ Oliver, #445
Class Struggle
Some folks here at the Sandusky Sailing Club may have a mast step template for you, or at least some measurments for it. Do you still need that info?
AJ Oliver, #445
Class Struggle
Re: Mast Step Measurements or Template
Dear Ron -
I did the measuring below for another 7.9 owner. Is it useful to you as well? If it is,
let me know and I'll do more (to help you situate the plate vertically).
AJ Oliver
Here is the first set of measurements. I'm trying to help you locate the mast
step fore and aft. Side to side you can do on your own. In a week or so I'll get you
the measurements from the metal plate to the surface upon which the mast step sits.
Apparently, the depth varies from front to back of the step.
I measured two different 7.9's - sail number 352 "Gargle Blaster"; and mine, # 445
"Class Struggle". I measured from the outer lip of the center board trunk (where the
lexan covers sit), to the center of the FRONT bolt holes. # 445 was 14 3/16" for both
holes. # 352 (which is having its mast step re-built) was 14 1`3/16" on the port side,
and 14 1/4 on starboard. (I used the front bolt holes because # 352 appears to have only
one rear bolt hole on its mast step [#445 has two]. You're gonna get some variation from
boat to boat, especially for those built some years apart.)
Here is the measurement from # 445 from the forward-facing side of the top of the
tang at the bow (where the forestay attaches) to the front of the mast step - 111 7/16"
Overall length of plate (# 445) 9 7/8"
Distance from front of mast step to edge of forward lip (where it starts to curve
downward) 5/8" - but your lip area was cut out, right? So this measurement likely won't
be much help.
Mast step measurements - front of plate to center of bolt holes - 1" Its also 1"
from the center of the rear bolt holes to the line in the rear of the mast step where it
starts to curve upward.
I'd also suggest that you find a 7.9 in your area to measure. It seems to me that
you can be off by 1/16" or so, and be OK - maybe even as much as 1/8", although that
would scare me a bit. I spoke with a master carpenter & boat repair guy (the one who is
working on #352), and he advises that for the height of the step you can be off by 1/8",
but that it's better to have the mast step 1/8" too low than 1/8" too high.)
Let me know if this info is useful to you. If it's not, please let me know asap. I
have lots of other things I can spend my time on.
Fair Winds, AJ (Skip) Oliver
7.9 #445
Sandusky Sailing Club
I did the measuring below for another 7.9 owner. Is it useful to you as well? If it is,
let me know and I'll do more (to help you situate the plate vertically).
AJ Oliver
Here is the first set of measurements. I'm trying to help you locate the mast
step fore and aft. Side to side you can do on your own. In a week or so I'll get you
the measurements from the metal plate to the surface upon which the mast step sits.
Apparently, the depth varies from front to back of the step.
I measured two different 7.9's - sail number 352 "Gargle Blaster"; and mine, # 445
"Class Struggle". I measured from the outer lip of the center board trunk (where the
lexan covers sit), to the center of the FRONT bolt holes. # 445 was 14 3/16" for both
holes. # 352 (which is having its mast step re-built) was 14 1`3/16" on the port side,
and 14 1/4 on starboard. (I used the front bolt holes because # 352 appears to have only
one rear bolt hole on its mast step [#445 has two]. You're gonna get some variation from
boat to boat, especially for those built some years apart.)
Here is the measurement from # 445 from the forward-facing side of the top of the
tang at the bow (where the forestay attaches) to the front of the mast step - 111 7/16"
Overall length of plate (# 445) 9 7/8"
Distance from front of mast step to edge of forward lip (where it starts to curve
downward) 5/8" - but your lip area was cut out, right? So this measurement likely won't
be much help.
Mast step measurements - front of plate to center of bolt holes - 1" Its also 1"
from the center of the rear bolt holes to the line in the rear of the mast step where it
starts to curve upward.
I'd also suggest that you find a 7.9 in your area to measure. It seems to me that
you can be off by 1/16" or so, and be OK - maybe even as much as 1/8", although that
would scare me a bit. I spoke with a master carpenter & boat repair guy (the one who is
working on #352), and he advises that for the height of the step you can be off by 1/8",
but that it's better to have the mast step 1/8" too low than 1/8" too high.)
Let me know if this info is useful to you. If it's not, please let me know asap. I
have lots of other things I can spend my time on.
Fair Winds, AJ (Skip) Oliver
7.9 #445
Sandusky Sailing Club
Re: Mast Step Measurements or Template
Guys, I would suggest that there are three important measurements, and I won't use the holes in the mast step plate because holes can vary. Also, the placement of the board trunk depends on the placement of the deck so I wouldn't measure forward from that and hope for much accuracy. I still have to do the same thing on my boat and I didn't bother measuring before I tore it all apart because the mast step area was already WAY compressed and distorted.
My plan is to make some quick templates (two other boats at the lake) of the mast step area on the front and from side to side, going from the inside edge of the antiskid all the way across for the latter.Then I will get the distances from the forward side of the stemhead fitting to the forward side of the mast butt, mounted in the mast step plate, and the vertical height of the MIDDLE of the plate, measured from a level jig made to sit on the inside of the toe rails and running across the middle of the mast step. The third measurement is the side to side, and that can be done with the same jig and a plumb bob to get center lined. Subtract the thickness of the mast step plate to get the finished deck height. Before drilling holes for the plate I will find the exact fore and aft (J) measurement with the same plumb bob and another hanging from a jig built to fit over the stemhead. Remember, this measurement (J) is the horizontal distance from the centerline of the forestay (extended), and deck(extended), parallel to the face of the mast, with the mast being vertical, NOT raked!!!!! Also remember to have the boat sitting level on the waterline all around.
The only rules that I can find concerning this are:
J = 9.5' (9' 6")
A1.B.3. The mast step assembly shall not be modified or relocated.
2.5.G.9.. J - Foretriangle Base: The perpendicular dimension between the forward most point on the face of the mast to
the plane described by the intersection of the centerline of the forestay (extended), and deck (extended), parallel
to the face of the mast.
2.5.G.13. SPL - Spinnaker Pole Length: To be measured with pole perpendicular to the mast and at right angles to the
fore-aft centerline of the boat: shall be less than or equal to 9.5' from the center of the mast ring to the outboard
end of the pole.
SPL is supposed to be the J measurement, and the designed J measurement was for a boat with a vertical mast.
I believe that this is all I need to know to get the mast step plate where it was supposed to have been WITH the correct J measurement, and I might add, closer than some of the stock boats!
Class dudes: please correct me if I'm missing something.
My plan is to make some quick templates (two other boats at the lake) of the mast step area on the front and from side to side, going from the inside edge of the antiskid all the way across for the latter.Then I will get the distances from the forward side of the stemhead fitting to the forward side of the mast butt, mounted in the mast step plate, and the vertical height of the MIDDLE of the plate, measured from a level jig made to sit on the inside of the toe rails and running across the middle of the mast step. The third measurement is the side to side, and that can be done with the same jig and a plumb bob to get center lined. Subtract the thickness of the mast step plate to get the finished deck height. Before drilling holes for the plate I will find the exact fore and aft (J) measurement with the same plumb bob and another hanging from a jig built to fit over the stemhead. Remember, this measurement (J) is the horizontal distance from the centerline of the forestay (extended), and deck(extended), parallel to the face of the mast, with the mast being vertical, NOT raked!!!!! Also remember to have the boat sitting level on the waterline all around.
The only rules that I can find concerning this are:
J = 9.5' (9' 6")
A1.B.3. The mast step assembly shall not be modified or relocated.
2.5.G.9.. J - Foretriangle Base: The perpendicular dimension between the forward most point on the face of the mast to
the plane described by the intersection of the centerline of the forestay (extended), and deck (extended), parallel
to the face of the mast.
2.5.G.13. SPL - Spinnaker Pole Length: To be measured with pole perpendicular to the mast and at right angles to the
fore-aft centerline of the boat: shall be less than or equal to 9.5' from the center of the mast ring to the outboard
end of the pole.
SPL is supposed to be the J measurement, and the designed J measurement was for a boat with a vertical mast.
I believe that this is all I need to know to get the mast step plate where it was supposed to have been WITH the correct J measurement, and I might add, closer than some of the stock boats!
Class dudes: please correct me if I'm missing something.