Original Engine Block Decked

[Troy P.]

Re: Original Engine Block Decked

My 63 fuelie original engine was decked in a rebuild and I'm interested in trying to raise the numbers. You can still see a tiny bit of two of them. Anyone know more about the acid process - such as what acid to use and how long it takes?

[Domenic T.]

Re: Original Engine Block Decked

My 63 fuelie original engine was decked in a rebuild and I'm interested in trying to raise the numbers. You can still see a tiny bit of two of them. Anyone know more about the acid process - such as what acid to use and how long it takes?

Troy,
you would probably be pleased at what you find because if one is trying to hide something they don't leave a little showing.
If you do the math on indicating the block surface with the crank when doing a pression bore one would wonder WHY the #s part of the block always has to go.
A .001 across the distance can get to be a lot at the other end and it always ends up the deepest at the #s for an unknown reason

If I needed to do it I would have looked into it already but I think a law inforcement lab or a good metallurgist would be a start and if it were mine I would want to know.
If you do PLEASE post it.

DOM

[Jack G.]

Re: Original Engine Block Decked

I remember as a young coin collector, being able to get a liquid (probably acid) from a coin shop that could bring back the dates that were worn off on buffalo nickels.

[Troy P.]

Re: Original Engine Block Decked

Dates on nickles. Interesting.

I'm confident that the engine is original. When I inspected the car before purchase I pointed out to the owner, who was not a died in the wool Corvette guy or numbers guy - just a car collector with a wide variety of cars, that the block had been decked during the rebuild he had done. He wasn't aware that had happened. Naturally I knocked $15,000 off the price for that issue.

This car had been his driver for many years until he decided to "restore" it. Well it sat in his barn, partially disassembled for 5-7 years until I came along to look at a 54 Corvette he had advertised.

[Tracy C.]

Re: Original Engine Block Decked

In some distant lands they use an acid to reveal the cast iron micro structure and the original numbers/letters pop out. Never tired it, might find something on the web...

Ron,

Raising numbers on cast iron with acid is another internet myth. Cast is to soft.

tc

[Domenic T.]

Re: Original Engine Block Decked

Ron,

Raising numbers on cast iron with acid is another internet myth. Cast is to soft.

tc

Tracy,
I was told of it back in the 60's before internet.

DOM

[Ronald L.]

Re: Original Engine Block Decked

Tracy, late 70's common practice. Distant land - only meant not USA, same technique...now if you end up int he hospital or blown up don't come crying to me, but if you can jump start a car with out exploding the battery, this may work...

the solution 5g copper sulphate, 60ml water, 30ml concentrated ammonium hydroxide and 60ml concentrated hydrochloric acid restored marks erased to a depth of 0.04mm below the depth, thus presenting itself the most sensitive solution. Another solution I have read about for etching steel is 50% hydrochloric acid with 5 gms. of cupric ammonium chloride added for each 100 ml. of solution. This solution is stable and may be kept indefinitely in glass containers with glass stoppers. To prepare 50% hydrochloric acid add one volume of concentrated hydrochloric acid to an equal volume of water. Always add acid to water never add water to acid. The etching solution may be applied with a cotton swab attached to a glass rod or a wooden stick. The etching can apparently be speeded up, and sometimes better definition can be obtained, if an electric current is permitted to flow through the etching fluid. An ordinary flashlight battery may be used to supply the electrical current. For better results from using the acid etching method you should remove scratches. Remove only enough metal to eliminate the scratches though. Remember the more level, smooth, and even highly polished and mirror-like the surface is the more successful the restoration will be. Remember that using acid may reveal the stamped number for only a brief moment so have a camera ready just in case.

[Tracy C.]

Re: Original Engine Block Decked

Ron,

It is my opinion that this is bunk...dreamed up by some internet crack head who wants to sound important. If it were possible, it would be common practice with examples readily availible for inspection among those in the automotive restoration hobby. After all....we have the internet and word spreads pretty quickly these days...

tc

[Jerry W.]

Re: Original Engine Block Decked

"The trouble with quotes on the Internet is that you can never know if they are genuine." Abraham Lincoln

[Tracy C.]

Re: Original Engine Block Decked

That made me laugh Jerry....Good one!

[Rick B.]

Re: Original Engine Block Decked

"It is my opinion that this is bunk...dreamed up by some internet crack head who wants to sound important."

I can vouch for Ronald Lovelace in what he has stated !
While I would have to look up the exact formula of the chemicals used to verify the mixture and concentrations, I have used this technique on recovered stolen autos where attempts were made to obliterate any evidence of the crime by grinding down the engine pads, as well as on handguns, both with considerable success.
The problem is there are no guarantees that it will work all of the time as too many variables exist to effect the final outcome such as initial force used in stamping the serial numbers as well as depth to which the destructive grinding occurred .
Most certainly however you must literally have a camera and tripod ready to go because the numbers appear and often disappear within a span of less than a minute. In the quest to raise the numbers this too is a destructive technique and the threshold or point at which you should stop applying acid is almost always too difficult to control - hence the transient appearance of the number(s). Rarely do all numbers appear uniform as well. This is likely due to the unequal force applied to all digits at the time of stamping and therefore the effect it had on the crystalline structure of the metal at the specific stamping site.

Rick

[Tracy C.]

Re: Original Engine Block Decked

Interesting Rick...what Ron posted was pulled from another forum posted by someone else and reportedly used in Malaysia. Since you have sucessfully done this and taken pictures of the result, please share them with us.

tc

[Domenic T.]

Re: Original Engine Block Decked

Rick,
Thank you for that, It validates what I said in my posts. It is chemistry mixed well with intellegence.
I am not a chemist or a metalurgist but i was told that the molecule seperation is what they pull out from under.

For the un-believers it is not hocus/ pocus.

Why don't we use it once here? well you know.

I would like to know how destructive to the #s it would be if it were used and documented once?

I would call it the pad polygraph

DOM

[Domenic T.]

Re: Original Engine Block Decked

This sounds like a proove it contest and there are many that would not want to proove it on their pads, or would they?

Sort of like the guy that refuses DNA tests, the guilty would want to hide this.

I know the stamps exhist out there because they were offered to me. If I decided to use them I would have no trouble telling the world. BUT what happens if 2 blocks come up with the same #s some day? Say one in a hot rod and another on a vette pad.

There is also NDT (non destructive testing) out there that we use on aircraft to detect problems that can't be seen by the eye. I have never used the equipment myself but it may have the quality to read anything that was put on a piece of metal after it was born.

DOM

[Rick B.]

Re: Original Engine Block Decked

As a police officer I have not been involved in this aspect of forensics since the mid 90's when I last utilized this technique on a batch of stolen cars that had been purchased by a dealership from across the country and sold to unsuspecting customers locally.
I can assure you the technique works but results are truly hit and miss given how aggressively and to what depth the numbers were ground down. I would often find that , for example, some digits would raise, then disappear just as others began to "come up", that is why a camera set up on a tripod, or a patient and willing diarist standing by to take notes is essential as the process is undertaken. For reasons that should be obvious I would prefer not to say to what depth numbers are no longer retrievable as this would likely assist potential forgers to thwart the ability to verify serial numbers.
The process works equally well on weapons and have successfully obtained serial numbers when the area was aggressively ground down !
Patience is the key to this procedure - don't expect too much too fast and it isn't neat and pretty like some staged television program. The digits will literally "raise" and then subside much like when magnafluxing a crack in metal.
I would not be surprised if some advances have since been made in terms of chemicals available to be used for this process but, as with most things, you probably don't hear much about the process because our disposable society and seemingly degrading work ethic (in all areas) makes this procedure too labour intensive for some to be bothered with. It is a shame, to be sure, but I can genuinely vouch for the authenticity of the procedure.

Rick