rivet bumps on hood of car

[mmay298]

Hi All,

new to corvettes and have a question. I have been looking at a 1972 that is local to me and I noticed that on the hood of the car there are raised bumps between the headlights and the hood. Perfect circles all the way across.

What are these and whats wrong? Are they fixable?

Thanks for the help
Mary

 

[sfallison]

That is a typical problem.. the aluminum rivits are showing through the fiberglass. The only way to fix that is to do body work..

 

[jdp6000]

Thats sounds common. The fibreglass is rivited and glued to the frame there. It sometimes pops and results in the headlight doors rubbing on the fibreglass. No big deal to fix.

Jim

 

[Twin_Turbo]

they are also a sort of blessing in disguize, you now know the front end is original.

 

[paintdaddy]

Thats not true.I just fixed some of these on a 69 yesterday,and yes the only way is to do bodywork.The front end on this car is very original

 

[Willcox Inc.]

The rivets popping up are the result of the aluminum rivet breaking down (corroding) between the header bar and the upper surround panel. When this happens they swell up and actually show up as pops in front of the hood. The only way to cure this problem correctly is to remove the header bar from the car and replace the rivets and/or the header bar. This is more common in cars that have spent most of its days as an outside car. It’s not an easy job to repair, but well worth the effort when it comes to a quality repair. The headlamps housings, supports and all brackets will need to be removed before you repair.

Choosing to just grind down the fiberglass that has risen up would also be a mistake! Doing this will only hide the repair until the rivets swell enough to show. Drilling them out from the top will only create a life long headache with hiding the holes you drilled.

Willcox Inc

 

[GTR1999]

The boys at Wilcox are correct.

The only real fix is to chisel out the support bar and this IS a big job. You have to remove the buckets then carefully remove the support which is bonded to the glass under the nose. Then you have to either get a NOS bonding strip and reuse the support or buy an after market support that is bent with the correct offset to eliminate the bonding strip thickness. Then use the correct 3m epoxy to set it in place. I set the buckets in place first and rig up clamps to dry set everything before trying to glue it in.This job plain sucks, sorry but there is no better way to describe it.
If you grind down the glass they will come back in time, if you drill out the rivets the holes will shrink- ever see a vette that had luggage rack removed and glassed over.

Good luck

 

[joe1975]

Yep! got one

 

[gmjunkie]

The boys at Wilcox are correct.

The only real fix is to chisel out the support bar and this IS a big job. You have to remove the buckets then carefully remove the support which is bonded to the glass under the nose. Then you have to either get a NOS bonding strip and reuse the support or buy an after market support that is bent with the correct offset to eliminate the bonding strip thickness. Then use the correct 3m epoxy to set it in place. I set the buckets in place first and rig up clamps to dry set everything before trying to glue it in.This job plain sucks, sorry but there is no better way to describe it.
If you grind down the glass they will come back in time, if you drill out the rivets the holes will shrink- ever see a vette that had luggage rack removed and glassed over.

Good luck

This is the right way!!!! And I'd rather have a Hot poker run up my A-->>...... Nose!!

 

[GaryS]

Thats not true.

Just curious. What is not true? Which statement are you referring to?
:confused

 

[iron cross]

The rivets popping up are the result of the aluminum rivet breaking down (corroding) between the header bar and the upper surround panel. When this happens they swell up and actually show up as pops in front of the hood. The only way to cure this problem correctly is to remove the header bar from the car and replace the rivets and/or the header bar. This is more common in cars that have spent most of its days as an outside car. It’s not an easy job to repair, but well worth the effort when it comes to a quality repair. The headlamps housings, supports and all brackets will need to be removed before you repair.

Choosing to just grind down the fiberglass that has risen up would also be a mistake! Doing this will only hide the repair until the rivets swell enough to show. Drilling them out from the top will only create a life long headache with hiding the holes you drilled.

Willcox Inc

Close, but not exactly the only way. Correct as to what the problem comes from. Not really a bad job if your familiar with fiber glass. The header does NOT need to be removed in most cases, nor the headlights, brackets, ect. However the rivets must be removed and as merely grinding is not going to fix it perminately.

 

[DINO71]

So once the rivets are removed the bumps disappear?

 

[Willcox Inc.]

How would you get the rivets out from between the header bar fiberglass bonding strip and the surround panel with out removing it?

I guess you could try to grind them out from between the fiberglass upper surround panel and the bonding strip, from the under side of the car?

The row of rivets that are toward the hood would not be that hard to get at, but the row toward the headlamps has restricted space. I’m not sure my gorilla hand will fit in there with a grinder.

We have a car on the lift right now at the shop; I’ll look at it later today. I’ve never tried to do this repair with the bar still in the car. I’ve always just removed it bar.

For sure, the topside approach is not the answer. Drilling out the rivets from the topside will do damage to the car that can never be fixed without showing!

 

[Willcox Inc.]

They won’t disappear, but they will settle down! After the bonding strip is glued back in the car you will still see slight raised areas. There is enough meat in the fiberglass that these can be sanded down and made smooth. Obviously this means you are painting the car again.

 

[bossvette]

are the rivots in the fiberglass or in the support, the 68 I just bought has them (pops) also and when its time to repaint I will want to deal with it.
My 76 the headerbar was so rusty it was not fastened to the fiberglass and had no rivot pops
So any info on this repair will be of future use to me.

 

[Willcox Inc.]

The rivets are sandwiched between the top of the bonding strip, number 13 and the underside of the surround panel where I’ve marked red in the picture. The rivets hold the bonding strip number 13 to the header bar number 11 in the picture below.

I went to the shop a little while ago and I really don’t see any way to remove the rivets without taking the bar out of the car.

 

[wallyknoch]

The rivets are sandwiched between the top of the bonding strip, number 13 and the underside of the surround panel where I’ve marked red in the picture. The rivets hold the bonding strip number 13 to the header bar number 11 in the picture below.

I went to the shop a little while ago and I really don’t see any way to remove the rivets without taking the bar out of the car.

Your asking for a lot of work and money by removing the header. The rivets can be identified by using a contrasting color of paint and spraying it on the front and board sanding the excess away. This makes a witness mark for all of them, and there is a bunch. close to 30 if I recall. The header is steel and the corrosion or rust is only near the rivets. Hole saw the rivets or bumps down to the header steel and "clean" the exposed plate with a twisted wire brush in a air tool or electric if no air is present. The rivets will come out. We then cut small circles of fiberglass mat with a sharpen piece of pipe and mixed them with the resin pushing them through the rivet holes thereby bonding the header to the top area and merely continued to build them up. In between the rivet holes now glassed and repaired we then cut more similar holes and used stainless rivets to bond the steel header to the upper glass panel and filled them as the rivet holes were done. Now everything is glassed together solid. Then merely finish the surface and prepair as any other section of the car by block sanding and priming. Do not use body filler. For those of you wanting pictures of the process just e mail me and I`ll be glad send photos from start to finish.

 

[Willcox Inc.]

Obviously there are varying opinions on which method is correct for the repair. One things for sure, we both agree that the rivets must come out! Sanding the area flat will only hide the problem.

It’s always been my rule to never drill a hole in any exterior panel to make a repair! I’ve never had any luck hiding the holes from luggage racks, extra antennas, carb stud holes in hoods ect… I have tried the mat and resin trick but eventually they (the holes) always come back to haunt me. So with this in mind, I would still take the extra time to pull the bar out of the car.

I really thought that I had missed something in the earlier post about how to get the rivets out. I actually though you had a way to get them out from the bottom…

 

[iron cross]

Fiberglass Race Cars

Obviously there are varying opinions on which method is correct for the repair. One things for sure, we both agree that the rivets must come out! Sanding the area flat will only hide the problem.

It’s always been my rule to never drill a hole in any exterior panel to make a repair! I’ve never had any luck hiding the holes from luggage racks, extra antennas, carb stud holes in hoods ect… I have tried the mat and resin trick but eventually they (the holes) always come back to haunt me. So with this in mind, I would still take the extra time to pull the bar out of the car.

I really thought that I had missed something in the earlier post about how to get the rivets out. I actually though you had a way to get them out from the bottom…

Why all the extra work? We dont hack anything. Just drilling a hole in fiberglass and perminately repairing it is a simple issue. We actually build and modify fiberglass race car bodies. Sometimes we have to nearly cut them in half because of wheelbase length, wheel well position, roll bar positions, and also chopping tops. One of them {AA Fuel Roadster} won the top show car award in America, the "Riddler Award". But experience helps plus using the correct materials. There are more difficult things to repair on Vettes than bumps on the front end.

 

[yarb]

The boys at Wilcox are correct.

The only real fix is to chisel out the support bar and this IS a big job. You have to remove the buckets then carefully remove the support which is bonded to the glass under the nose. Then you have to either get a NOS bonding strip and reuse the support or buy an after market support that is bent with the correct offset to eliminate the bonding strip thickness. Then use the correct 3m epoxy to set it in place. I set the buckets in place first and rig up clamps to dry set everything before trying to glue it in.This job plain sucks, sorry but there is no better way to describe it.
If you grind down the glass they will come back in time, if you drill out the rivets the holes will shrink- ever see a vette that had luggage rack removed and glassed over.

Good luck

This is top of the line advice. Had a corvette resto shop at one time . This is a major job if done correctly. A quick fix will be an on going headache.Those rivets are aluminun but they do deteriorate causing the circular bumps you refer to. If you have no corvette/fiberglass repair experience, bit the bullet, find a body shop that REPAIRS CORVETTES regularly and get the job done correctly. If you havent bought the car you might want to pass on it. This repair is labor intensive and accordingly will be expensive.