Any of you have a recommendation for someone to shot peen a set of rods for me? Or, do you know how to do shot peening in a media blast cabinet?

 

Well, I may have answered my own question, but I'd still like your input. Anyway, I think I've found the place for having shot peening done. Talked to Fred at United Plating Work and took these notes:

• $75 for a set of 8 rods if they have to mask the bores, and $50 if not
• They are an aerospace company and do it quite scientifically. They measure the thickness of the part and refer to a MIL Spec that gives them the guidelines as well as the required test strips. They load up with the appropriate shot, set the PSI, and shoot against a test strip that must arc to a certain height. Then they shoot the part, and then shoot a test strip when done to prove they are still in calibration.
• A media blast cabinet like mine won't have enough vacuum to pull the steel shot properly. They use an elevator system that raises the shot above the work and then introduce the air as the shot falls.
• Proper shot peening increases the fatigue life 10x. For instance, if you took a part that would work-harden and fail after 10 bends and shot peened it the failure point would be somewhere beyond 100 bends.

 

Just as a follow up, here's what I posted in Dad's Engine thread on the 80 - 86 forum:

 

Sorry to be a noob here but what was your reasoning for this? I'm no metallurgist, but wont that change the actual hardness of the rods, I know it essentially gives them a tough skin for crack prevention, but isn't there a bit of elasticity needed?

 

Here's a blurb from http://en.wikipedia.org/wiki/Shot_peening on shot peening:Fred said that if you were able to shot peen a piece of wire that would normally work-harden and break when you bent it 10 times, that it would go over 100 times after shot peening. And he basically said I won't be able to break those rods, that other parts of the engine are now the failure point, not the rods.

 

Read the article and I'm sold, looks like that will be the standard in my rotating assemblies going forward. Thanks for the great info!

 

No problem. By the way, will you be home in the September time frame? I plan to have another get-together at my place for the only FTE chapter that is OK and would love to have you come and meet the folks.

 

I wish, I haven't been home since 2011 this is my 1 trip home for this tour here. It's just too darn expensive to fly the whole family home(3.5k), but in the next few years ill be looking for an Engineering job in the area, and hopefully finally settle down.

 

Hope that works out for you. We lived in the UK for a while and travel home was certainly expensive, so I understand.