bolt restoration

[Michael H.]

Hello everyone, I'm in the process of organizing bolts and fasteners for replating. I have a question as to when not to restore? I've got some bolts that are too rusty to make out the headmarks. I'm also wondering about bolts that need to be torqued. Should I replace them with new any that need to be torqued? I've read in the archives a previous post on embrittlement.
Also, I could use any info on bolt location & identifcation such as the best publications etc. I read in the archive about a computer version 66 AIM database. Any info on this would be a help. Thanks. A reply would be greatly appreciated.

[Jack H.]

Re: bolt restoration

If you see excessive rust (comments to the effect that this/that fastener is so rusted the headmarks can't be distinguished), I wouldn't try to 'save' that fastener.

On hydrogen embrittlement, yes that CAN happen. But, if your platter is competent, he'll have down pat the process to thwart the problem.

Basically, you can get H2 bubbles 'trapped' in porous base metal surface pockets that wind up being plated over. Their migration into the base metal over time can result in fastener fatigue/failure.

The 'fix' is pretty simple. Once a part has been initially plated, it's 'cooked' in an oven to cause trapped H2 bubbles to expand and out-gas. Then, the fasteners are given a quick 'swim' back though the plating tank to re-seal the microscopic 'breach' areas of the plated surface that opened up during the anti-embrittlement treatment process.

Our local cad plating shop, routinely does work for FAA and NASA qualified projects. It's a no cost adder for them to put parts through their anti-embrittlement process after initial plating and their treatment meets US government standards...

[Scott S.]

Re: bolt restoration

Also, I could use any info on bolt location & identifcation such as the best publications etc. I read in the archive about a computer version 66 AIM database. Any info on this would be a help. Thanks. A reply would be greatly appreciated.

I've been thinking about this too. I have all the bolts, nuts, washers etc. bagged and identified, but when I send them to a plater, it's going to be one big bag of parts. What is the best way to separate them out when you get the re-plated pieces back, if you don't have the experience to simply recognize what goes where?

[Jerry B.]

Re: bolt restoration

Hello Folks ,Years Ago I Completed A Total Nut And Bolt Restoration . I Used A Copy Machine For Identification And Location Notes on All The Fastners. This PROCESS Saved Many Hours Of Reassemble TIME. Thanks