CORVETTE TIPS AND TECHNIQUES

1961-62 INSIDE REARVIEW MIRROR


The inside rearview mirror (ISRVM) on the 1961-62 Corvette is usually in poor condition when you happen to find a car which still retains its original one. That is, the metal face is rusted and pitted. As a matter of fact, most of these early cars have already had their ISRVM changed.


I wondered why so many have been replaced. After all, this is a part you don't usually think about, and it's inside the car where you would think it would have been protected from moisture and corrosives. I have even noticed a rusted mirror on a car where all the other chrome plating was in good original condition.


I finally figured out the reason for this: the ISRVM on the early Corvette was plated with an inferior plating at the factory. Unlike the rest of the plating on the car, it received chromium plating without the benefit of the copper plate underneath. This is the reason the plating didn't last.


Why, you ask, was the ISRVM the only part on the car, which was plated this way? Read on....


Please look at the photos of the original 1961-62 inside rearview mirror and the replacement mirror, the one you usually see in place today. As you can see, these mirrors are similar in so far as they both have the same overall shape, the same type screw stud for mounting, and the same style mirror glass which is fixed and not able to be adjusted for night time use. Differences include the fact the mirror is dated on some of the replacement mirror glasses, where the old original mirror glass was not. The original mirror has a flat face, about 1/8" wide pressed around the circumference of the metal housing, and the glass is crimped into the housing. The replacement mirror glass has been glued into place. The metal housing has not been crimped around the glass. The replacement mirror is much heavier than the original, but it is a good-looking piece and it has a much better plating job on it.

























The 1/8" flat face around the circumference of the original mirror forms a ledge, which rested flat on a support while the glass was placed into the housing and a press die was able to crimp the edge tightly around the glass.


The 1/8" flat face was the surface upon which the mirror rested as the pressing operation took place. The glass was beveled around the circumference so the metal case could be formed up close to the glass.


Speaking of the glass, it's not the same as regular mirror glass like you have in your bathroom. This mirror glass is very different. First, this glass is 5/64" to 3/32" thick. This is not a standard thickness for mirror glass. Additionally, this mirror glass is what most of us would refer to as "two-way mirror glass". That is, it can be used as a mirror on one side, and if you look from the other side, you can see through the mirror. Also, the mirror silvering is placed on the outer face of the glass, not on the backside as you might expect. You can check a mirror to see which side of the glass the silvering is on by touching a pencil point to the glass. If the point appears to touch the image pencil point, the silvering is on the outer face of the glass. If, on


the other hand, the points appear to be separated slightly, the silvering is on the other side of the glass.


The reason the silvering is placed on the outer face of the glass is to reduce glare, especially during nighttime use. This two-way mirror glass is used because a percentage of the light hitting the mirror is absorbed through the silvering and is lost in the non-reflective surface behind the glass. This is why you will find a piece of black paper or a piece of masking tape behind the glass when you take the mirror apart. If you used regular mirror glass, the glare of headlights at night would most certainly blind you. Incidentally, good quality outside rearview mirrors uses the same method of reducing glare. Check yours and see if it has the silvering on the outside surface.




























The disadvantage of this type of mirror is it is somewhat delicate. If you use an abrasive to clean the glass, it will scratch the silvering.


Remember that I mentioned the fact the ISRVM was the only part to receive an inferior chrome-plating job, a process without the copper plate under the chromium? The reason is if a copper plate were used, the mirror housing would not crimp over the glass without cracking the plating. When you use a triple chrome plating process, it is somewhat brittle and it cannot move and bend fat enough for the crimping operation to be successful without damaging the chrome plate. If you eliminate the copper plating process, the chrome-plated housing will crimp around the glass without damage to the bright finish. The disadvantage is the part will corrode with ordinary use, from the elements as well as from the oils from people's hands, and its life will be greatly reduced. This explains the fact that on an otherwise well cared for car, with good plating, the ISRVM will often be the only part, which is deteriorated.


Another difference is the original mirror had the word "GUIDE" printed in a slight curve around the base of the mounting stud. The capitol letters were approximately 1/16" high and the word was centered below the stud. The original mirror had two rivet heads visible on the metal face exactly opposite each other, at the three o'clock and nine o'clock positions. These rivets, along with two other parts hidden inside the housing held the threaded stud in place and provided the friction to help keep the mirror in the proper position.







































I haven't had experience with the earlier ISRVM used on the 1958-1960 Corvette, but I believe that much of what is being discussed here will apply to that mirror also. A photograph of an earlier mirror is included. It is rectangular, and has three rivets instead of two. The stud is the same as the 1961-62 mirror.


I looked long and hard for a good mirror for my 1962 Corvette, and I never found one. So I decided to try to restore my original mirror to its former condition. In doing so, I realized I would have to make a decision as to whether to break the glass, or to try to get it out without damaging it. For many of you, that decision will be easy because the glass is already broken or it is so badly scratched that you would not want to use it again.


I would say there are two ways to go about restoring these mirrors. One way would be to break the glass and leave the original crimp around the mirror case, and have a glass shop cut a new glass, which would fall into the case and be held in place by an adhesive. The other method would be to pry open the mirror case, remove the glass, and later re-crimp the case over the original glass, or a new one, to achieve the original appearance. I have restored these mirrors both ways, and, with careful workmanship, the results are equally good.


As a matter of fact, I have found the biggest problem with restoring these mirrors is getting the chrome plating done satisfactorily. I have sent in mirror cases that were in poor condition and had them come back as good as new, and you could still read the word "GUIDE" exactly as before. And, I have also had just the opposite result. Often the problem is the fact that the plater has to buff the metal case enough to achieve a smooth surface, and in doing so, the word "GUIDE" is lost. As you can see, the protection of the stamped-in logo is an important part of the restoration.



















THE NEXT STEP:


1. Un-crimp the case to remove the glass, and then re-crimp it again so it looks as though it was never disturbed.


2. Remove the rivets, get new correct rivets for free, and re-rivet them to achieve a tight adjusting mirror that will not fall down when you hit a bump in the road.


3. Get a bright new shiny case, with the word "GUIDE" perfectly lettered in it without getting it chrome plated.


4. Find the correct mirror glass, for the glass shop to cut to shape, because the glass shop probably won't have it in stock (I tried many glass shops and had no luck at all).


Meanwhile, if you intend to restore one of these 1961-62 mirrors, go to a couple of good swap meets and look for mirrors that resemble to ones shown in the photos. Don't worry about the glass, or the stud on the back. Try and find a mirror case in good condition that can be used as it is or possibly a mirror case out of a truck, which was originally painted and therefore has no pitting. Better yet, try and find a mirror case in stainless steel, which can be buffed to a chrome-like brilliance without any plating. Oops - That was the secret from (3) above (these were used in several GM cars in the sixties).




I mentioned there are essentially two ways to restore these mirrors. One way would he to un-crimp the case, remove the mirror glass, replate the housing and then  re-crimp the glass into the case. The other way would be to break the glass, leave the crimped edge in place, plate the housing, and replace the glass by means of an adhesive.


In the first instance, the mirror case would have to be plated using the original process whereby the copper plate was not used. If the copper plate is used, the case will he too brittle to crimp around the glass. As you will recall, an alternative would be to use an old mirror with a stainless steel case. In this example, the mirror would look exactly as the original did, but it would be detectable by means of a magnet. For those of you who want to stay with the original design, use a plain steel case, and either of the two plating processes mentioned above.


I would like to follow the format that I mentioned above:


  1. (1)Un-crimping the case is not difficult with the use of a special tool which can be made out of a small pair of slip-joint pliers. These small pliers can be purchased at any good hardware store. They need to be modified by grinding the first tooth on the fixed jaw as I have done. As you can see in the photo, the first tooth is very sharp and because of this, it is able to fit into the tiny space between the mirror glass and the metal case. When grinding the pliers, be sure to have some water nearby so you can keep the pliers  cool. Do not let the metal become blue, as the hardening of the teeth will be lost. The second photo shows how the pliers are held to grasp the case. By swinging the handles downward, the case is un-crimped little by little. It isn't necessary to un-crimp the entire case to get the mirror glass out. If you un-crimp the shorter of the two long sides, and the two ends, the mirror glass will fall out. In un-crimping the case, make small movements as you go. That is, unfold the crimp in steps, a little at a time so the metal isn't stretched too much. If the metal is stretched out, it will not re-crimp later because it will be too long. That would leave folds along the edge of the crimp, and it will be obvious that the case has been pried open. With care, the un-crimping can be done in such a way that it will re-crimp smoothly, and there will be no telltale ridges left along the edge of the glass.


When you open the case, you will find a piece of black paper or a piece of masking tape behind the glass. This is intended to help absorb light for night time use. Often, the paper is distorted due to moisture getting into the case, so you will have to go to a stationary store and get some fresh paper with which to cut a new one.


(2) Under the black paper, you will find the spring plates and rivets. I recommend you grind off the heads of the rivets using a Dremmel Tool or similar grinding device. Do not grind the rivets on the outside of the case. Do your grinding on the inside, where it will not be seen later.


I mentioned above that you could get new rivets for free. I purchased the original rivets for these mirrors in a lifetime quantity. I mean a lifetime, and all of your lifetimes combined. It seems the rivet  manufacturer only thinks in terms of thousands. In any event, we have enough rivets to restore all the Corvettes ever made.


If you will send me a stamped return envelope, I'll be happy to send you a pair of rivets.


The new rivets will be exactly the same as the ones originally installed in the mirror. In order to install them so as to keep the rounded top on the rivet, you may want to make a punch with a recess in the end of it as I did. As you can see in the photo,I have ground a dish shape in the end of the punch so as to cradle the head of the rivet. This helps to protect the shape of the rivet head when you are peening over the opposite end. Another photo shows the relationship between the rivet and the punch. The dish in the end of the punch is made by grinding with a small grinding wheel while turning the punch. Once again, a Dremmel Tool is ideal for making such a shape.


I stand the punch in my vise as shown in photo #5 and, having a helper hold the mirror properly, I peen the rivet using a small ball-peen hammer. I have found I can peen the rivet just enough to provide a tight fit on the ball stud. The way the spring plates are arranged inside the mirror, the stud should remain tight if the rivets are properly peened. Use no lubricant on the ball stud, it needs to have a fair amount of friction on it. 


At this point, you would be ready to either install a new mirror glass and crimp the edges, or glue in a glass prepared by a glass shop with a  silicone glue. I have used several types of glue and I find a clear silicone glue works best. In any event, don't forget the black paper behind the glass, because if you do, you will be able to see inside the

mirror case, right through the mirror glass, in some light conditions.


(3) We have considered the possibility of using the stainless steel case, and I believe the advantages and disadvantages of its use have been covered. The stainless steel case as well as the chrome-plated steel case (plated without the copper layer) will un-crimp and re-crimp properly using the procedures outlined earlier.


The method of crimping the case is quite simple. Using a small ball-peen hammer, tap the edge of the case with hundreds of light taps, moving slowly around the edge of the case. Use the fat face of the hammer, not the rounded ball-peen end. Sit down and hold the mirror case, with the beveled glass and the black paper sheet in place, and take all the time you need. Each tap will move the metal just a tiny amount. In this way, you will be able to reform the crimped edge, and it will look just like it did when it was crimped in the factory.


(4) The mirror glass is a special type (dark shaded, silvered front), and it is not usually available at a glass shop. I have found that it is available under the Roberk name, and it is a truck mirror replacement glass. It is cut to the size of the most common outside rear view mirror on many light trucks (7" x 10"). This glass has rounded corners, and it is intended to be installed in the truck mirror case using the original rubber retainer ring. A glass shop should be able to trim this replacement to the size and shape needed for the Corvette mirror.


A photo shows the small hammer I have used to work on these mirrors.

  

I have enjoyed experimenting with this project, and I have learned quite a lot while doing so. I have been able to restore several of these early mirrors, and they have passed the inspection of both the judges at Bloomington,

and the NCRS judges.


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InsideMirror.pdf