I'm going to make my own strut, so I have a couple of questions. First, what's the hot ticket AFA strut bushings for 1 1/8" GN style strut, and the other queston is how much press is there between the bushing and the strut?
Thanks in advance.
Also, if anyone needs one made, I might as well make two or three while I'm at it. Let me know.
This is an area I leave to the people that make these for a living....chromoly steel, high tensile stick rod and heat treating are best left to the pro's in my opinion. The correct bore for 1 1/8 is 1 3/8 exact....let the bushing provide the press fit not the bore of the strut........just my .02
This is an area I leave to the people that make these for a living....chromoly steel, high tensile stick rod and heat treating are best left to the pro's in my opinion.
Definitely. The strut is the "lifeline" of your boat. It's well worth the money to spend whatever they want for a good one.
I planned on making my own strut because I intend on changing prop shafts up to 1 1/8". I intended on making it out of stainless material.
I've fabricated steel for decades, have had all position stick welding certifications and have no reservations about making it myself.
Is that a fact or a speculation that the boughten struts are indeed made out of chrome moly material ? Alloys typically don't stick weld good and are crack prone on heavier materials.
I would have guessed that they were made out of cold rolled mild steel which would stick weld good and flex with out cracking.
The strut that I have in there now is an 8 degree strut but I determined that the strut is mounted at a 7.5 degree angle to the keel.
Unchained,
not trying to bust on you at all but how did you measure the angle and get so accurate?
Can you walk me through the steps to do it?
I have always wondered how the placement of the prop shaft/strut is determined when installing into a new boat. How is all that figured out?
Also, why would you stick weld the parts as opposed to mig or tig?
Be good, Jim
I have a digital protractor that I measured the angles with.
I zeroed it out on the prop shaft and then put it up against the keel.
It's got a V groove on one side that sits on the prop shaft nice.
It was great for setting up the motor and trans mounts too.
http://www.jlindustrial.com/ProductI.../MT9-50315.jpg
I got it on sale a couple years ago for about $ 189.00 from J & L industrial supply.
The reason for stick welding is to make a heavier cross section weld in a single pass and have less shrinkage.
TIG makes a small bead. You could make several passes but that causes a lot more distortion/shrinkage. TIG causes a lot of distortion because of the slow travel speed.
MIG would probably work OK on mild steel.
I've got a dual shield MIG machine that would make a heavy weld also for mild steel.
For stainless with 1/2" plate material I would use stick and V it out at the joint.
Why not make it out of a single piece of billet? You could go with either stainless or carbon steel.
If you decide to make a stainless strut i'd highly recommend using 17-4 alloy stainless, it can be heat treated after you have finished fabricating it, and it is by far the best stainless to work with for machining and welding.
For strut bearings we use the 'Special' Morse rubber bearings from glenwood. they have been good for us over the years. 1 3/8" bore in the strut. As I'm sure you know try not to get an extraordinary amount of heat into the weld between the bore tube and the strut itself, they can warp pretty easily, ruining all your hard work.
Good Luck!
The Steel struts are Heat treated...
I have a digital protractor that I measured the angles with.
I zeroed it out on the prop shaft and then put it up against the keel.
It's got a V groove on one side that sits on the prop shaft nice.
It was great for setting up the motor and trans mounts too.
http://www.jlindustrial.com/ProductI.../MT9-50315.jpg
I got it on sale a couple years ago for about $ 189.00 from J & L industrial supply.
The reason for stick welding is to make a heavier cross section weld in a single pass and have less shrinkage.
TIG makes a small bead. You could make several passes but that causes a lot more distortion/shrinkage. TIG causes a lot of distortion because of the slow travel speed.
MIG would probably work OK on mild steel.
I've got a dual shield MIG machine that would make a heavy weld also for mild steel.
For stainless with 1/2" plate material I would use stick and V it out at the joint.
OK, gotcha....
I was trying to figure out how you transfered the measurements from the top side of the boat to the bottom with 1/2 degree accuracy. Digital protractor sure would make that an easy job!
On the welding, I would of think a short mig pass (1" or so) then cooling off then more welding would create less distortion than a heavy stick weld. But you are right, stick will fill in a large area in one pass. Would you pre-heat stainless?
Reminds me of a story a friend of mine told me once.
This guy was fabbing up stainless tanks for Genesee beer here in Rochester NY. Big tanks that they walked on while working to give you an idea. I would guess 20-30' in diameter. To weld the top on, they had a real big mig welder on tracks that did the welding all by its self. If I remember right he said they had 1/4'' wire in it. Huge amperage. Said when it struck an arc, there would be a deafening bang like an explosion. They used to wait until the executives or a tour came by just to scare the chit outta them LOL...
I bet that machine would weld up your piece in one pass !!!!
Be good, Jim
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