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View Full Version : 1982 S&S Pylon Reinforcement Mod.


Olaff
07-21-2014, 12:24 AM
I was noticing a little fore and aft movement on the tow pylon in my 600-hour 1982 Stars & Stripes Powerslot. When I say "a little" let me quantify it with about 2 inches of play at the top of the pole. Enough so that it was getting close to touching the engine cover with a load on it.
So beginning last weekend I undertook what I thought was going to be tightening a few bolts. I had done this once before when I bought the boat last year with 498 hours on her, but found it quite difficult to reach under the floor and access all the bolts from the engine opening. So I removed the driver's and observer's seat bases to give myself some room to work, disconnected the battery and removed the battery tray.
When I pulled out the battery box I noticed 30+ years of accumulated bilge crud in the forward bow that I couldn't leave uncleaned. At this point I decided I was just going to remove the floor panel in front of the engine that the pylon pokes through to get good access to the forward bilge, and pulled back the original carpet very careful with full expectation of putting it back in place within the hour.
After a good cleaning and hosing everything aft, I noticed 3 problems;
1. Water accumulates in the bow area of the bilge and the fiberglass buildup under the pylon mount acts as a dam to keep the water up there from draining aft.
2. The floor mount for the pylon was loose and moving in the fiberglass bedding in the hull, squeezing water and muck out with each push and pull of the pole fore and aft.
3. Of the 8 bolts that mount the trans-stringer pylon brace in place, 3 of then were totally "wallered" out and had no hope of being tightened.

Here is the pic of the original floor mount after I cut away the little bit of fiberglass that had it mounted in the floor:

Olaff
07-21-2014, 12:26 AM
You can see the 4 thru-hull holes, 2 each fore and aft of the pylon base, which is where the bolts for the forward-most tracking fin come through to bolt it in place.

Olaff
07-21-2014, 12:35 AM
Since fiberglass resin doesn't adhere to metal very well, I decided that the 4 bolts that mount the tracking fin would make an outstanding way to really strengthen the base mount's installation. The idea being that I sandwich the fiberglass hull between the tracking fin underneath, and the pylon mounting base above.
I found that a 6" x 6" steel plate 1/8" thick would provide the perfect size to accommodate this. I cut the plate, measured, drilled and tapped the holes for the 3/8-16 bolts and set it in place to check alignment of the holes.

Olaff
07-21-2014, 12:38 AM
I used the plate to trace the outline where I would grind away the surrounding fiberglass to provide a level and flat surface for the new bigger plate to mount in.
Upon removal of the base plate I found that there were a few voids where the factory glassers had left an air bubble or two in the resin. These pockets were full of muck. After cleaning you can see that the bubbles are the cleanest spots (look at the elongated pocket on the port side).

Olaff
07-21-2014, 12:39 AM
Next I used a rotary rasp on a cordless drill to grind away the high spots and prep my mounting area.

Olaff
07-21-2014, 12:40 AM
I also opened up any voids I could find between the 'glass layers to ensure there were no loose spots.

Olaff
07-21-2014, 12:43 AM
Next I layed a layer of 24 oz. fiberglass filler cloth into the hole that the original base mount had come out of, mixed a batch of resin, and poured it in to bring the low spots up to the level of the surrounding ground-down surface.

Olaff
07-21-2014, 12:45 AM
I removed any rust or residue from the bottom of the base mount and mig welded it to the center of my 6'x6" plate.

Olaff
07-21-2014, 12:47 AM
Now came setting my bigger base to the hull. I cut a piece of 6oz cloth oversized from my base and cut holes to match the thru-hull holes.

Olaff
07-21-2014, 12:50 AM
Here is the new post-machine, welding, grinding, primed, and painted base mount setting in it's new bed of resin.

Olaff
07-21-2014, 12:55 AM
Let it cure overnight, then went out this morning to install the tracking fin and blots. I was actually pretty proud of my precision in machining this thing as after a quick clean-out of the threads with the tap the bolts went right up and through with a nice tight fit. I loaded the tracking fin base and all the bolt holes up with a good layer of sealant (not 3M 5200 in case I ever need to disassemble), and tightened the plate down from underneath. Once everything was tight and I ensured that I had a uniform and sufficient squeeze out of sealant around the fin base, I went top-side and installed the washers, lock washers, and nuts.

Olaff
07-21-2014, 01:01 AM
Here is a close-up of the finished product. Now not only is my pylon base never going to go anywhere, but I have also reinforced the leading tracking fin.

As I was mixing the several batches of resin for the base mount, I packed fiberglass cloth into the trans-stringer bracket mounting holes and filled them with resin as well. This should give me a good solid mounting point for that. I ran out of time this evening and had to go put the steaks on the grill for dinner, but I am going to pre-drill the newly reinforced stringer holes and remount the upper bracket this week.

I have an idea for handling that low spot in the forward bilge that I am also going to address later this week. Posts and pictures to come!

Olaff
07-26-2014, 03:49 AM
So after thinking about the physics of whats holding that bracket tight, I cane up with a better idea than lag bolts. I'm not sure if the lag bolts that were in mine were stock or from a previous owner, but they were 3/8" lag bolts screwed through a 1/2" hole in the bracket and into the stringers. That means with even just a little loosening of the previous blots the bracket has an opportunity for movement.
So I went to my local bolt supply this morning and got 8 what he called "long nuts". They are stainless steel, and measure 1/2" thread by 1 1/4" long. A 3/4" wrench or socket fits the nuts, but if you measure across the widest point it is 7/8" across. I also got 8 matching 1/2" x 1 1/4" stainless steel bolts with washers.
Here is the fun part... I decided to "rough up" the outer surfaces of the nuts and flush-mount them into the stringers with epoxy. To keep the epoxy out of the threads while they were setting, I taped the "deep" ends of the nuts with masking tape, then set them open-end-up on the bench and filled about 1/4" with candle wax to keep the epoxy out. I drilled out the original 3/8" holes in the stringers with a 3/4" bit so I would have a REALLY tight fit (remember these nuts measure 7/8" at the widest point), filled the hole with epoxy, and hammered each nut into its hole with a deadblow hammer until flush at the surface (with the bolt screwed in about 1/2 way).

Olaff
07-26-2014, 03:55 AM
It did take a little work to get the 1/2" bolts in the 1/2" holes lined up with the 1/2" threads, but I got all 8 in and there was absolutely no play even before I tightened the bolts.
I took a pic of the final product before I did some other work (see "Antique S&S Bow Bilge Doesn't Drain") and installed a new floor section. But the picture came out blurry and now it's all put back together.
I'm going to open it up again after boating season is over ( late October) and I'll snap a pic and post it then.

Miss Rita
07-26-2014, 08:30 PM
Beautiful job, great craftsmanship!

CruisinGA
07-26-2014, 10:00 PM
Your a "belt and suspenders" kind of guy, aren't you?

Nice work!

Olaff
07-27-2014, 11:06 AM
Your a "belt and suspenders" kind of guy, aren't you?

Nice work!

Ever heard of the "6 P's"
"Proper Preparation Prevents Piss Poor Performance"

We have big genes (and jeans) in my family. I'm 6'4" and 250#. My 16-year old son is 6'5" and 210#. I have 3 more kids behind him that are packing away the groceries. The kids love to go doubles and we have pulled triple a few times. That pole is going to see a lot of strain in the coming years.

6gun
07-29-2014, 07:59 AM
Nice job! Looks like you can even pull tubes and big stuff. I hesitate to pull tubes from my pylon and only use my lift ring at the stern because of the massive amounts of stress tubes put on rigging getting on plane, but I love the cross-brace idea. Well done!

Olaff
07-29-2014, 10:06 PM
Thanks 6gun.
I had 2 kneeboarders and the oldest son on a wakeboard at the same time all attached to the pylon this evening. I had the corner of my eye on that pole at each pullout, it never budged!
You don't have the same pylon setup in the Maristar, do you?

6gun
07-31-2014, 12:24 PM
Thanks 6gun.
I had 2 kneeboarders and the oldest son on a wakeboard at the same time all attached to the pylon this evening. I had the corner of my eye on that pole at each pullout, it never budged!
You don't have the same pylon setup in the Maristar, do you?

Very similar...mine mounts to the hull at the base, but has (2) U-Bolts through a floor support cross member about 10" up from the hull mounting point. Never budged...except for 1 time when I was pulling a tube from the aft lift ring and wanted to shorten the rope and just looped the rope still tied to the lift ring around the center pylon....increased the mechanical advantage to the point where the pylon was bending 2"-3" inches....not recommended or tried twice...quite remarkable.