I am in the early stages of restoring my 65. I want this car to able to Top Flight on its first attempt. How important is it to use original bolts? Does it make sense to change the interior wiring harness as well as the eingine compartment harness? It seems a little crazy to use old fatigued bolts, nuts and harnesses but it seems that there exists some extremism in this hobby when it comes time to judge, having read some of the entries on the forum.
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Re: Reusing old bolt, nuts, washers and wiring harness
If the bolt head markings are legible and threads are good and the nuts are not too rusty, I would stick with the originals. Same goes for the wiring harness. If there is no fraying, cuts or breaks or even only minor repairs needed stay with the original. Your interior harness should be fine if it hasn't been exposed to the elements. The engine compartment is up to you, but remember to keep the old harness for some of the new connectors are not exact and should be replaced with the original ones. -
Re: Reusing old bolt, nuts, washers and wiring harness
Martin-----
Most of the fasteners on a Corvette are not safety-critical. So, in most cases fasteners can be re-used without creating too much of a problem. However, even in these cases, if there is any damage to a fastener such as significant corrosion, etc., I would not re-use the fastener.
For SAFETY-CRITICAL fasteners, that's another story. These include most suspension, brake, steering and engine fasteners. In these areas I'm reluctant to use old fasteners unless I carefully inspect them for even the slightest damage AND I know the history of them. In other words, I KNOW that they've never been subjected to excessive application of torque. How does one know that? I can better answer by saying how one doesn't know that. If you purchase a fastener from a box of used fasteners at a swap meet, you don't know the history of it.In Appreciation of John HinckleyComment
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Re: Reusing old bolt, nuts, washers and wiring harness
When you start laying out big bucks for all new harnesses that don't match the originals, and new reproduction fasteners made in China, this thought will not only make sense, you will be wondering why you ever considered buying new. Reuse every thing you can.
In this case, I disagree with Joe. If you are going to be beating this car around the track full-out, I would replace the critical fasteners with new, but only with made in the USA, ASTM certified, head stamp "go to hell" fasteners. But...since you may never get it back to the lawful speed limits, I wouldn't worry about reusing old fasteners. If they weren't too fatigued/broken when you removed them, they won't be any "tireder" when you put them back.
Any refinishing you do should consider the need for post-plating stress relief, but I'll take a good ole tired Detroit bolt over a brand new Chinese copy any day (Can you spell melamine?...Or wheat gluten?). To the degree that available reproductions are made in the USA and identical to the original fasteners in all respects, I have no objection to replacement...but, just try to get that info out of your usual vendor.
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Re: Reusing old bolt, nuts, washers and wiring harness
There are pro and con arguments for going both ways (preserve and reuse original fasteners & wiring harness OR change them for decent quality new ones). YOU have to be the judge/manager of the restoration project and make the call. Here are a few considerations that others haven't discussed.
(1) While reproduction wiring components are NOT 100% authentic (can't be due to changes in construction, DOT requirements, and lack of original tooling as well as materials), you're getting brand new wiring that isn't oxidized, embrittled, and meets today's quality standards. Ever see one of these cars burn due to an electrical fire? It's NOT a pretty sight...
(2) If the replacement fasteners are properly manufactured, you know you won't be fighting the threat of fatigue fracture.
Last, if your only aim is to achieve Top Flight (versus going to the top of the mountain for Mark of Excellence), then you need 94% during judging. That means you can afford to lose 6% or 270 judging points.
The deductions for different 'incorrect' fasteners and detectable reproduction wiring components are typically minor. A point here, another point there. You've got 270 to sacrifice in your pursuit of the goal... Play the game to your economic and peace of mind advantage!Comment
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Re: Reusing old bolt, nuts, washers and wiring harness
Martin, having read what was said before, I am in agreement with
most of the comments. Ultimately its your choice. If you decide to
use reproduction fasteners, please e-mail me. I will be happy to buy the
originals you have. I only use original fasteners in my restorations.
Thanks and good luck
JGComment
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Re: Reusing old bolt, nuts, washers and wiring harness
How many of us have worked on original cars that were never taken apart in 30 - 40 years. The bolt head markings still look O.K. but the bolts shear like butter with hand tools when we try to remove them! This includes bolts such as bumper and leaf spring not just small fasteners. Sorry guys, bolts are subject to the second law of thermodynamics like all other things. They start out as robust U. S. made bolts, but after some torque to yield occurence or a few decades of deterioration they are no stronger than cheap repro's and at some point they will actually be weaker. If you want a car you will only trailer then 50 year old originals are O.K.Comment
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Re: Reusing old bolt, nuts, washers and wiring harness
"Shear like butter"??!!...Actually, torsion is a kind of shear, but shearing is when you cleave the fastener in half by applying a lateral load through the fastened components.
If your personal experience is that original Grade 8 and Grade 5 fasteners twist apart without a substantial loss of cross sectional area due to rust, better check the head stamps...you may already have been victimized by imported fasteners.
We are NOT talking about fasteners that are rusted half way through. Inspection is a critical step in the decision to replace or restore. If the head stamps are unreadable and the threads are deterioated, there is no point in a restorer wanting to reuse them anyway.
The failure mode of concern here is fatigue. When fasteners fail by fatigue, they appear in sound condition, but fail completely and suddenly without warning. On aircraft and other structures where weight is a concern, engineers reduce weight by designing for stresses that will provide a finite number of load cycles. Old aircraft exhibit fatigue failure in the skin by cracking, because the skin is a structural part of the aircraft. That's why the number of landings an aircraft makes between inspections is important.
On heavier materials like steel, engineers can often design for stresses that will provide a very large number of load cycles. In many cases, the number of load cycles is infinite for all practical purposes. Tractors and 35 year old automobiles would fall into this category unless they have been continuously abused by misuse or poor maintenance. Fatique failures are observed in such machinery, and high stress fasteners would be likely candidates, but there is almost always another contributing factor like unbalance that increases loading beyond design.Comment
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