1969 Spare Tire Tub Question

[Kevin S.]

I am in the process of restoring a OEM lower spare tire tub for a 1969 Coupe. I bought this tub on Corvette Forum a couple of years ago. The part numbers match my AIM. Descrition of the tub and rivets match up with my 6th edition judging guide book. This tub will replace a GM Service Replacement tub that was on the car when we bought it in 2009 as part of my NCRS restoration journey and eventual judging down the road.

My question: Was there a rivet protective coating applied on the inside of the tub? Reason I say "rivet protection" is that you can see in the attached photos where it looks like someone sprayed a coating over top of where all six rivets are located that secure the V-strap to the tub. The rivets are upfacing and unique as decribed in my book. Book makes no mention of any coating over top of the rivets. Maybe a past owner sprayed something on top of the rivets to protect them or to protect the spare tire?

Thank you advance to your comments and observations.

Kevin

[Jeffrey S.]

Re: 1969 Spare Tire Tub Question

Kevin,
Someone else can jump in and correct me if I'm wrong but it appears that the rivets are installed here upside down. I believe that the flat side of the aluminum rivet is facing the spare tire and the "hammered" side is on the metal strap. That is the case in all rivets that I am aware of. The machined flat side is on the fiberglass and the punched side on the metal side. In this application the flat, smooth side is where the spare tire is and does not need to be covered by anything.
Jeff

[Michael G.]

Re: 1969 Spare Tire Tub Question

Correct Jeff.

[Kevin S.]

Re: 1969 Spare Tire Tub Question

Hi Jeff,

Ah bugger! I took out a magnifying glass and I am able to see that indeed the V-strap support is riveted in the wrong direction on page 256 of my 6th edition 1968-69 TIM&JG. My book shows the hammered side of the rivet on the bottom of the tub next to the V-strap support. Perhaps this is why the tub was for sale a few years ago.

Would you, or anyone else, happen to know where I can source the correct rivet? Book says (P.256), "the rivets, after upsetting, are unique in apperance to the spare tire tub and are not used elsewhere on the car". I am interpreting this description to mean that these are not a typical autoparts store run-of-the-mill aluminum rivet? Must be some kind of heavy-duty rivet to hold the v-strap and support the weight of a spare tire?

Kevin

[Kevin S.]

Re: 1969 Spare Tire Tub Question

Update:
I went on to the Covette Central web site and ordered two (2) set of six rivets to secure the v-strap. If CC sells it, it has to be right! Right?

Once the rivets arrive in the mail, I'll clarify / verify that they are okay for NCRS judging (that they look correct) and then drill out the old rivets and install the new ones in the correct orientation. Ordered two sets of six rivets so that I can practice setting and hammering the rivets into place like on P. 256 of my book.

Kevin

[Michael G.]

Re: 1969 Spare Tire Tub Question

There was a particular "domed" finish to the hammered end of the rivet when complete.

[Jeffrey S.]

Re: 1969 Spare Tire Tub Question

Kevin,
When you do the repair, here are a couple of things that I found helpful. First, only take one rive off at a time and install a new one before moving to the next one. When I have done this and the strap was completely off I used screws and nuts to temporarily hold the strap in place. You will need a helper to "buck" the rivet. I bought the cheapest air hammer that Harbor Freight had (like $10 for the set) and hollowed out one of the round chisels. Set the air pressure very low and you should make a factory like peen. Hope this helps.
Jeff

[Joseph W.]

Re: 1969 Spare Tire Tub Question

The old rivets on your tub are also incorrect. There are no holes in the rivets.
I just finished restoring my 69’ tub and ordered the rivets from ZIP ( Mine were a little long, but since they are aluminum, easy to shorten).

I bought an inexpensive air chisel from Harbor Freight and then ordered some tips for the air chisel off EBay.
258D0549-1B78-4FA6-90FD-55E1879BF84B.jpg
I used the second tip from the left and ground it down so the cupped part of the tip was wider to accommodate the rivet.

Turn the air way down on your compressor and I used a sledge hammer as a bucking tool to set the rivet.
Turned out great!

[Jeffrey S.]

Re: 1969 Spare Tire Tub Question

We were typing at the same time!
Jeff

[Kevin S.]

Re: 1969 Spare Tire Tub Question

Hey Michael,
I have a rivet set punch with the "domed" tip and should be able to duplicate that finish. Thank you.

[Kevin S.]

Re: 1969 Spare Tire Tub Question

Hi Jeffrey,
Oops...I got a shot of liquid confidence and went ahead and removed the v-strap. Figured it has to come off anyway as the rivets were installed wrong and the rivets were the wrong type anyway (hollow shaft).

I will use the nut and bolt idea to hold the v-strap in place - good idea. I will use a helper to hold the tub too - good idea. I am going pick up the Harbor Freight air hammer you mentioned and the chisle set the Joseph found on eBay. Those will make the job a little easier. As mentioned in the reply to Michael, I have a "domed" manual rivet punch tool also that I can use with a hammer to help make the final rivet finish look correct.

Thank you for all the good tips and suggestions.

[Kevin S.]

Re: 1969 Spare Tire Tub Question

Hi Joseph,

I will do the same. Thank you for the eBay link and the how-to suggestions.

[Patrick H.]

Re: 1969 Spare Tire Tub Question

You may was well blast and repaint the V-strap while you're at it.

[Kevin S.]

Re: 1969 Spare Tire Tub Question

Hi Patrick,

Agree, it's the perfect time to make it look as good as I can get it. I was happy to see the underside of the v-strap once I took it off the tub. It's in really great shape, just a little minor surface rust.

Once bare, I was planning to use self-etching primer and then finish with semi-gloss black. It'll look really nice when it's done.

[Kevin S.]

Re: 1969 Spare Tire Tub Question

Thank you all for your advice and suggestions. I have everything that I need:

1. I'll go to Harbour Freight today 01/15/2024 and get the cheap $10 air hammer
2. I ordered the 6 pcs air hammer rivet setting tool set on eBay 01/14/2024, will arrive in about a week
3. I ordered two sets of v-strap rivets (2x6 pcs) from Corvette Central 01/14/2024, those will arrive in about a week
4. I'll drop the v-strap at my local sandblaster and get that stripped, will pick that up 01/17/2024
5. Then, self-etch prime and semi-gloss black paint the v-strap
6. Once the rivet sets arrive, I'll practice setting / bucking the rivets to match the photo in my NCRS book with a "domed" finish
7. With the v-strap off, I'll finish wet sanding (600-1500) and cleaning the lower tub inside and out
8. Finish the tub by applying a very light mist coat of matt clear acrylic lacquer to the inside and outside of the tub
9. I have a rubber stamp to apply the date code (AUG 27 1968) to the ground-facing side of the tub after the v-strap is reattached. I picked August 27, 1968 since it is about two months back from my car's build date October 30, 1968

Thank you NCRS smart dudes!