need help determining what kind of metal?

[prunk14]

noticed a few cracks in the tower at the last race. Took it to the local welding garage and had no luck in talking them into repairing.

I needing to find out if anybody know what kind of metal these are built with. Does not rust like stainless steel but its magnetic.

Anybody know who fabricates this towers for the Yamato 80

[roperz111]

Stainless steel properties

Stainless steel types that are in the 300 series (304, 316, etc.) are not magnetic. However, stainless steel types that are in the 400 series
(406, 410, 430 & 440) can be slightly magnetic.

Hope this helps.

Chris

[machinedcomp]

Towers

It looks like mild steel that has been Nickel plated. The plating prevents it from rusting. It should weld up just fine.

[bill van steenwyk]

Before you weld on the tower.......................

........you may be wasting your money if you do not find out what caused this.

Usually, but not always, when a tower breaks the cause is imbalance of the powerhead of some type such as modifications to the engine that cause it to turn much higher RPM than it did when stock, or more likely the powerhead is not in perfect alignment with the mounting for the lower unit you are using causing strain or side load on all parts of the tower. Usually where it breaks when this is the cause is the weakest point. Alternate firing two cylinder engines of the Yamato type are some of the worst with this problem.

Sometimes this will also be indicated by leaking seals in the top of the lower unit or bottom main seal if bad enough. Normally though they look like yours with this problem.

If it belonged to me I would take it back to the person who built it (looks like they did a nice job welding wise) and ask them to check and see it the mounting for the powerhead and lower unit are square and true and in the same plane. Things can warp during the welding process and if not trued up after welding you end up with this problem.

If the person that fabricated it knows what they are doing they should have that equipment on hand. If not, a real easy cheap way to do it is put it in a fixture you know is square in a mill and take a real fine cut on the top and bottom. If it is NOT square it should be very obvious with the first fine cut you make, on either end.

Any number of folks have this equipment probably including your local machine shop if you cannot find someone familiar with fabricated tower housings in the time frame you have.

Welding it without knowing whether it is square to start with is like marrying a girl without being sure she has matching equipment to yours!

Good Luck



ADD:

You did not put up a good enough photo of the powerhead mounting plate to really tell, but on the lower unit mounting area the vertical pipe used between the two mounting plates does not seem to go all the way thru the bottom plate. Traditionally the best way to fabricate these towers is to make the vertical pipe portion go all the way thru the mounting piece, maybe even in an "interference" fit with the plate heated and the pipe cooled before insertion so you are not just depending on the weld to hold the two together but have additional strength by having the pipe inside the plate. This makes it much stronger and not so likely to come apart catastrophically if the weld fails. Like everything else there is a good, better and best way to fabricate things.