tig welding

[johnsonm50]

If you dont know if its magnesium pour vinegar on it!!! Vinegar acts like acid on mag and makes it smoke!!!! If its aluminum its just like pouring water on it!!

Thanks, thats good to know.

[Blackhawkguy]

Try................

I weld propellers with Aladin, it works great on white metal and crummy aluminum, the problem is it needs a backing plate to hold form, it melts at around 750, it's a gas weld rod. I also notice when props come back and the area around the weld was thinned out the blades have a tendancy to break at the weld, its a scarf joint so the weld did not fail but just more brital at that point. Try anealing the tower after welding to take some of the hardness out, or try a diferent rod, there is a rod that works good with aluminum with allot of silica in it, I cannot remember the number but have some at the shop and will try and give it to you tomorrow.

Kerry

[johnsonm50]

I weld propellers with Aladin, it works great on white metal and crummy aluminum, the problem is it needs a backing plate to hold form, it melts at around 750, it's a gas weld rod. I also notice when props come back and the area around the weld was thinned out the blades have a tendancy to break at the weld, its a scarf joint so the weld did not fail but just more brital at that point. Try anealing the tower after welding to take some of the hardness out, or try a diferent rod, there is a rod that works good with aluminum with allot of silica in it, I cannot remember the number but have some at the shop and will try and give it to you tomorrow.

Kerry

Thanks, Is Aladin similar to alumaweld? It also melts around 700 but doesnt work well building up an area. The job is done, ended up plating it with sheet aluminum. We accidently found that it welded to the tower no problem.

[Skoontz]

What George was saying makes sense regarding the eggshell theory. We have welded some aluminums before and it actually separated as though it was layers of aluminum foil. The weld hung on to the top layer, then it just peeled off like after you take the potato off the grille and put it on your plate.

[johnsonm50]

What George was saying makes sense regarding the eggshell theory. We have welded some aluminums before and it actually separated as though it was layers of aluminum foil. The weld hung on to the top layer, then it just peeled off like after you take the potato off the grille and put it on your plate.

Ive heard that about flywheels but the towers aren like that.

[Blackhawkguy]

yes

yes the Aladin is simular to that type of rod, it has to be backed with something or it will run off on the floor, you also have to tin it like soldering, but I have repaired some white metal brackets and stuff with it, glad you got it fixed. I have tig welded a swivel bracket on a Mercury outboard and I was a little nervouse about it holding but the guy is still using it, you just need to take your time and v-the living daylights out of it.

Kerry

[johnsonm50]

yes the Aladin is simular to that type of rod, it has to be backed with something or it will run off on the floor, you also have to tin it like soldering, but I have repaired some white metal brackets and stuff with it, glad you got it fixed. I have tig welded a swivel bracket on a Mercury outboard and I was a little nervouse about it holding but the guy is still using it, you just need to take your time and v-the living daylights out of it.

Kerry

Thanks Kerry, The stuff I prepped is V-ed out well and the welds despite the difficulty look real good. For the moment Ive got a small mapp gas torch, I think the alum / solder stuff has potential if you use an oxy. / acet. welding torch. Mapp or propane just take too long to heat large material & is hard to mate large to small + the backing up to hold it from running out like water.

[hydroman6]

Used to use some stuff called Everdure. It's a Bronze/Silicone gas rod, but is used as a braze welding rod which needs oxy. acet. at > 850 degrees. Worked on cast aluminum engine blocks in a car racing application. Castings (older) have silicone and even some ferrite material in them. Welding on new aluminum pieces works because the new aluminum is diluting the "bad" things in the casting which increases weldability of the material. Might try a clean aluminum (consumable) backing plate and wider groove opening if you have the room. Just a thought without seeing the actual configuration.

[johnsonm50]

Used to use some stuff called Everdure. It's a Bronze/Silicone gas rod, but is used as a braze welding rod which needs oxy. acet. at > 850 degrees. Worked on cast aluminum engine blocks in a car racing application. Castings (older) have silicone and even some ferrite material in them. Welding on new aluminum pieces works because the new aluminum is diluting the "bad" things in the casting which increases weldability of the material. Might try a clean aluminum (consumable) backing plate and wider groove opening if you have the room. Just a thought without seeing the actual configuration.

Thanks, I dont think any other board would give as good 411 as here.

[Blackhawkguy]

the other thing

yes acetalene works better, you have to get it hot to tin it then after that it does not matter, I tried a propane oxy set up but it did not get hot enough quick enough, I was welding around 60 props in 3 hours at the time so I neeed fast and hot. Also remember the thinner it gets the more likely to break it is, keep it at least 1/8 inch thick. Also run the acetalene rich like a shielding gas. Ok.......... enough of my 2 cents

Kerry

[johnsonm50]

yes acetalene works better, you have to get it hot to tin it then after that it does not matter, I tried a propane oxy set up but it did not get hot enough quick enough, I was welding around 60 props in 3 hours at the time so I neeed fast and hot. Also remember the thinner it gets the more likely to break it is, keep it at least 1/8 inch thick. Also run the acetalene rich like a shielding gas. Ok.......... enough of my 2 cents

Kerry

Good to know, thanks Ive always got some aluminum fabricate /repair thing goin.

[johnsonm50]

Some pics of the big block OMC tower...



theres the old tower that was cracked at a rear powerhead bolt hole, a lower mount bolt hole & bent in the submerged object strike I mentioned.

<a href="http://s35.photobucket.com/albums/d151/mes355/?action=view&current=013.jpg" target="_blank"><img src="http://i35.photobucket.com/albums/d151/mes355/013.jpg" border="0" alt="Photobucket"></a>

This is a fit-mockup not the finished product. It weighs 78 pounds and is 18 1/4" from transome mount to center of propshaft & can be run with several HPs inc. a 35. It has 14:15 gear ratio and will go nicely on the hydro.

<a href="http://s35.photobucket.com/albums/d151/mes355/?action=view&current=015.jpg" target="_blank"><img src="http://i35.photobucket.com/albums/d151/mes355/015.jpg" border="0" alt="Photobucket"></a>

Ive done a little to the small block one to but will finish this one 1st [for obvious reasons] will post more done, Thanks for all your input. Mike

[greenmerc]

tig welding

even if its properly welded it wont hold if the machine work isnt right!!! all surfaces must be flush and square.

[johnsonm50]

even if its properly welded it wont hold if the machine work isnt right!!! all surfaces must be flush and square.

Even Tho I carefully set this up and jig-ed it well some expected distortion occurred. I checked/rechecked and adjusted the surfaces to be parallel. When the foot is on the tower the driveshaft centers well in the machined O ring seat. I think itll be OK. When I did the foot adapt a couple years ago I had trouble, brought it to a good machinist to surface and insert SS sleeves w/ shoulders its been fine since & Ive learned what to look for.
I use a sink cutout from a granite countertop as a flat surface, as good as glass & hard to scratch. I contact cement a couple pieces of sandpaper to it close together and its a fine surfacer.

[Fast Jack]

Home made tower another direction

Why not pick up a Yamato tower and make a powerhead adaptor plate. This is a lot stronger, and will get the overall length of the motor down to work on a hydro . Unless you plan to troll with it you dont need a water pump. We put a Yamato foot on a 55 H and it cools fine .