I was getting ready to re-install the door hinges onto my '81, checked the Assembly Manual and I had not noticed that an adhesive is called for between the body and the shims....???...GREAT!....what adhesive do I use? The stuff I took was of course all dried-out and crumbled and fell off.

Only thing that comes to mind is the adhesive caulk that I have used on bath fixtures.

Need some insight here as to what to use......

Thanks in advance.

 

Probably doesn't matter. I'm thinking just for ease of manufacture or to keep them in line while tightening the bolts.
Not a expert here.

 

It may say adhesive, but it's serving as a sealer to keep water from finding a way in.

 

So like silicone?

 

I would use seam sealer, just brush some on

 

Okay seam sealer; now I just need to find a small quantity of this as I need so little.
Going to check with my paint shop and see if I can get a small amount from their supply.

I was going to put black RTV around the shims and hinges to keep water out, but the word "adhesive" was making me wonder if this was needed in securing the shims and hinge to the body. Although with four bolts in such a small area I did not think that an adhesive was necessary.

Thanks for the responses.

 

If the car is not painted yet, stay away from silicone.
Even as a sealer, don't go all wild and spend a lot of money. Literally thousands of products out there that will work.

 

That is exactly what I do not want to do....buy an entire can of seam sealer for the very small amount that I would use.

So if this is "adhesive" is really just to keep water out, then since the car has been painted (well...in this area anyways...still waiting for other parts to be painted)....sounds like I could just use some black RTV around the shims and hinges...???

Would this cause any problems??? Sure is a lot easier to get RTV than go to the body shop and beg, steal, buy some seam sealer from them. They are a good hour round trip from me. What else would work that is easy to find??


I removed all the rust from the shims and painted them...same with the hinges.

 

The bath tub calk or the rtv would probably be ok. It's ment to hold up to moisture. You're not going to see it anyway, right?
I would use whatever you have on hand or buy a tube of exterior calking from the hardware store for $4/$5.

 

One will see a bit of the "adhesive" when the door is opened and looking at the hinges.
Think I will just go with black RTV as the car has been painted black, same for the hinges and shims and this way it will blend-in. The bath tub adhesive caulk is white to off-white and would really show-up against the black paint.

Thanks to all for the replies, clarifications, and suggestions....this is what makes this forum such a resource.

 

Please, Please, Please, do not use RTV. If you want to seal it and make sure no water gets in, remove one bolt at a time, put caulk or sealer in the hole and then put the bolt back in. This is not a job for RTV slathered onto the outside of the hinge.

 

Okay....got to ask why this is not a job for RTV? I was thinking that a small bead around the inside perimeter of the first hinge and then a thin layer around the outside perimeter of the shims and hinges would be just the thing to do.

Why is this a bad thing?

 

RTV is the most incorrectly overused product ever made.

In order to seal the contact area between the hinge and the body, it works best when the sealant is used as a type of formable gasket between the two parts. The best sealant is body sealer. When a bead is applied to the hinge and then torqued into place the sealant will of course squeeze out as the hinge is tightend. It will also squeeze in and surround the bolt holes. After it cures it will remain adhered to the metal and be flexible for the life of the vehicle. It is also not permeable by water.

Now you may say, "I can do the same thing with RTV." You can. There is nothing to stop you, but the RTV is too thin. Applied the same way as body sealer it will end up too thin between the hinge and the body. The amount that squeezes out will not adhere to the painted metal as well and will eventually begin to flake and allow the water to flow past it.

In the case of the original question, the writer has installed the hinges without any sealer and does not want to remove the hinges. This is understandable. I hate adjusting doors also. The temptation is to apply a bead of silicone around the outside of the hinge where it meets the body. Black RTV on a black car seems to be logical. There are a couple of problems with this approach. First, RTV will not adhere well to painted metal when you feather the edge. Second, the edge will allow water to get past since there is no sealer formed gasket between the hinge and the body.

My suggestion of removing one bolt at a time will not affect the door adjustment. Body sealer can be inserted into each bolt hole. When the bolt is installed it will force the sealer around each bolt and some will be forced between the hinge and the body. The head of the bolt will then seal the outer hole in the hinge. Of course, it will not be as good as the sealer installed first but it is more effective than trying to seal it from the outside around the hinge.

You are of course free to repair your Corvette any way you want but I have learned from years of experience that RTV has it place, but this is not one of them.

Thanks

 

If you want your paint to stay..DO NOT USE RTV. Give it time...you will see. It is the wrong product...plain and simple...much like so many people reach for windshield urethane and use it like it is a "fix-all" product ...when it is clearly NOT. If you want to...use it... and do not read any more.

Use the correct seam sealer like SEM seam sealer (long work time) and quit trying to find a substitute due to costs. ( Sorry---but DAMN). The reason is...IF you use what you think...and it fails...the problems you will have will out weigh the costs of doing it correct the FIRST TIME. Sorry...but I use only the right stuff because I am doing this on peoples Corvettes...and I have to guarantee my work. There is a lot of seams you can address...so it will not be a waste. It is the "costs" of doing something right.

Also...you will want to make sure the post is clean and rust free and primed with PPG epoxy primer....I prefer black epoxy. Also the hinge being clean, rust free and primed...and then also the shims being rust free and primed. I can not tell you how many hinge posts I have had to sandblast to get clan before I primed then. NO substitute for doing it right....and also dig out and replace any old factory seam sealers that have cracked. And you can use whatever you want on the bare steel...but you will be on your own if you choose to use an aerosol product. Trying to "re-invent the wheel" here ....can be...in time....catastrophic!!!! Do not ask me how I know this.

I apply a thin coat between the shims after I have gotten my set-up achieved. I them apply a thin amount on the hinge post and attach the hinge and tighten it up. Them...one at a time I remove the bolts for the hinges and apply a little on the underside of the washer of the bolt and re-install them and them take my finger and apply some sealer around the washer if it did not squish out when tightened.....then I go on the top of the shims and apply a bead of sealer so water can not find its way between anything....depending on if it also squished out when being tightened. You do not have to "butter" the entire surface of the shims...just the top and sides...because water can not run upwards.....and it makes it so the shim packs are not glued together....just in case you have to get back into them and do adjusting for some odd reason.


Seem like a lot of B.S. to you...well....do it another way...which is up to you...and then water test your car only to see water coming into the hinge post from eh hinge are and them I will clearly hear you cussing that you "WOULDA-COULDA-SHOULDA".

I only am writing this because I have BEEN THERE!!!!!! If that is not enough for you...then you have already made up your mind and are going to do what you want...or are waiting for some confirmation from someone who will agree with your thoughts so you can end up doing it the way you want to anyway.

DUB

 

I have absolutely not made-up my mind to use a certain material.....this is why I ask.
I ask because I have not done this in the past and want to learn from those that have.

However I will not blindly accept one material over another without any type of explanation as this does not provide any learning.

Now DUB and jcuprisi have provided pretty darn good rationale....thank you, and others have also suggested the use of seam sealer as well.

The shims and hinges are not installed yet...just hanging there with the bolts just started in order to hold them in place. NO alignment has even been attempted yet. The paint shop painted over the post area which I had cleaned all of the old "adhesive" off and taken-down to bare metal before car was taken to the paint shop.

In using seam sealer will I need to remove the paint where the shim and hinges mount to?

 

If your posts were cleaned, primed and rust removed BEFORE you painted it so you know that the hinge post is "SPOT-ON" correct...then the paint is a sufficient foundation for the sealer to adhere. As long as it is grease/oil free...you should not have a problem...other than the color mat effect how the hinge looks when completed...which might require a paint brush touch-up to hide the seam sealer. The shims need to be addressed....or at least I would.

DISCLAIMER:
If you are going to use a seam sealer from "whom-ever". Take the time to call them and talk to them about what you are planning, and find out the working time. Many seam sealers are catalyzed and have a certain amount of working time before it begins to gel up and get a skin on it. Some seam sealers are NOT catalyzed...and when applied...if the seam sealer applied is large/thick enough..it may take some time to skin-over...and even though it is "paint-able"....what may occur is the paint will crack due to the curing and out-gassing of the solvents in the seam sealer.

DUB

 

You can just use 3M dumdum (3M 8578)
GM used it in many areas where the sealer had to remain plyable.
One other area is the ttop ss trim to prevent leaks.