Radiator & Support Finishing..and other Qs

[Keith M.]

So rad and support are pulled and ready to go to shop for a copper radiator recore. see pix. This shop seems more than experienced but I want to ensure I direct them as needed for correct finishing of rad and support. Goal here is NCRS judging standard.

The radiator seems pretty straightforward. JG p193 says rad is "painted with a heavy bodied gloss black paint. It is applied sparingly and results in a rough texture."

Rad support - JG isn't real clear on orig finish other than to say "This support was in place during body paint and engine compartment blackout operation, and thus, paint overspray from either or both may be present." My gut says a likely original finish would something like a typical chassis paint...satin? Any input appreciated.

Also check out the two tags. No idea what the "21136" tag is about. The other one seems to placed right where one would expect the orig "MK" tag. Perhaps applied during a long ago rad refurb?? Any thoughts on the significance or meaning of either of these?

And I do realize the overflow hose nipple is toast. Planning to get that repaired during the recore. And the cap is not correct...already have repro one.

Anxious to get them off to the shop but wanna get it right cuz a do over won't be fun!!
Thanks!

[Keith M.]

Re: Radiator & Support Finishing..and other Qs

BTT. Does anybody have any advice, input, knowledge of correct finish for a radiator support? Anyone have a photo of a 69 showing the radiator and support so I can at least get a sense of how to finish the support knowing how it looks against a radiator? Do I go with a generic semi gloss or satin chassis black? Anxious to get the rad and support off to recore and refinish. Any guidance much appreciated.

[Patrick H.]

Re: Radiator & Support Finishing..and other Qs

Odds are that if you sandblast your radiator support, it's toast. These rust out VERY quickly. The reproductions are very good, and it's rarely worth repairing an original.
They were originally painted black; the Dupli-color semi-gloss is likely a close match. They will then show evidence of blackout paint AND often evidence of body color pain, as they were present for both of those processes. Follow my link below, and see yellow in spots on my support of my 72.

I use Eastwood's radiator paint for my radiators, and specifically ask the radiator shop NOT to paint the radiator when they recore it. Use some wax and grease remover on the tanks, then paint.

I would suggest that both of the tags on your radiator are non-factory, and I would remove them.

Take lots of photos of where your original seals are placed. Do NOT throw them away.
When Doc Rebuild opens again for business soon, get new ones.

[Mike E.]

Re: Radiator & Support Finishing..and other Qs

The 21136 tag is a radiator shop addition.

[Keith M.]

Re: Radiator & Support Finishing..and other Qs

Odds are that if you sandblast your radiator support, it's toast. These rust out VERY quickly. The reproductions are very good, and it's rarely worth repairing an original.
They were originally painted black; the Dupli-color semi-gloss is likely a close match. They will then show evidence of blackout paint AND often evidence of body color pain, as they were present for both of those processes. Follow my link below, and see yellow in spots on my support of my 72.

I use Eastwood's radiator paint for my radiators, and specifically ask the radiator shop NOT to paint the radiator when they recore it. Use some wax and grease remover on the tanks, then paint.

I would suggest that both of the tags on your radiator are non-factory, and I would remove them.

Take lots of photos of where your original seals are placed. Do NOT throw them away.
When Doc Rebuild opens again for business soon, get new ones.

Thanks for that input. For refinishing I was not contemplating sandblasting but rather along the lines of 1) WD40 to get the main crap off, 2) then try like naval jelly or EvapoRust, then 3) repaint. I attached a few pics of the rad support including close ups of the lower two corners. In my assessment they should clean up ok as I do not observe flaking layers of rusted steel. Repro one is $370...plus tax and possibly shipping unless i wait for next free shipping. But this does lead into a general question I have been thinking about with regard to judging. Of the two alternatives...a nicely cleaned up and repainted original core vs. a repro...how are they viewed in terms of judging. Is one more desirable or does it end up being a "depends which judge you get" subjective thing. The balance or trade off here is...originality that shows signs of age....vs...a repro which looks very good but obviously not original. I realize decisions like this in large part depend on the priorities and goals of the restorer...and I am trying to figure out where i come out as I start this restore. In the case of this core...I am inclined to clean it up and refinish. Now if it were in much worse shape...and/or we were talking a $20 part...i would probably feel differently.

Paint - thanks for all the tips. If the recore shop is well experienced on painting and I give them verbatim painting info from the JG...any reason NOT to have them paint the rad tanks? Just one less thing for me to do...and easier to paint when apart. Just curious.

Seals - GREAT advice. Already been around in a circle a bit on these but believe I have landed in the right spot. Ordered a full (wrong) set from Zip which I learned I need to return. It is a tricky proposition to get all the right seals....350/350, copper rad, N40 but no A/C. For my config ..air dam seal is the 3 piece one..simple...no baffle in my car so no baffle seals. That leaves the four rad seals and the four seals for plastic shroud. My pics show the four rad support seals still in place...the seal on top of the radiator as best I can tell is fan shroud seal that "welded" to the rad. Repro seals have holes in them and I read about push in fasteners...but there are none of those on mine..and don't really see any corresponding holes they would go into to hold seals in place. Seems adhesive was only thing used. As for Doc Rebuild....been watching for to them to re-open for some time now...so may just have to use Zip, Paragon, whomever. Curious if anything better about the ones Doc has?

Also, why NOT through away the old seals? I get the idea of using locations of old ones to place new ones...other than that??

Thanks SO much for all the guidance.
Keith

[Joseph S.]

Re: Radiator & Support Finishing..and other Qs

Keith, I doubt you will get a replacement core from a radiator shop that will be a match to the original core. You will probably need to get a core from DeWitts.

As far as the radiator shop painting....same thing goes....I doubt you will get an acceptable paint job from your radiator shop unless they are well tuned to dealing with "Restorations"

If you are not communicating with them about all these details, you will get whatever their normal mode of repair is.

[Patrick H.]

Re: Radiator & Support Finishing..and other Qs

My rule - NEVER throw away an original Corvette part.
If nothing else, you're going to need the seals to put the new ones on. I usually try to match the original install as close as able.

You can try your way of painting the support, but they rust from the inside out. Don't do it halfway, because you already know how much time and effort it will be to pull it all out just to rehab/replace the core support.

The radiator shop won't paint the parts prior to assembly, and as Joe notes they won't do as nice of a job as you would.
Be sure they use your original upper and lower supports, as discussed previously.

[Keith M.]

Re: Radiator & Support Finishing..and other Qs

Keith, I doubt you will get a replacement core from a radiator shop that will be a match to the original core. You will probably need to get a core from DeWitts.

As far as the radiator shop painting....same thing goes....I doubt you will get an acceptable paint job from your radiator shop unless they are well tuned to dealing with "Restorations"

If you are not communicating with them about all these details, you will get whatever their normal mode of repair is.

Thanks Joe. Good advice. This shop seems versed in doing radiator restoration. Recommended to me by a knowledgeable and respected source and I spoke to them directly about my expectations and am comfortable. I will reiterate finishing details when I drop it off. I did look at Dewitts and maybe they have replacement cores...but could not find anything on their website other than full rads and aluminum only at that. But if I get stuck or uncomfortable with my local shop..in terms of matching orig core... Dewitts is the first place I will turn. And will paint rad and core (tanks/bars) myself if needed.

[Keith M.]

Re: Radiator & Support Finishing..and other Qs

My rule - NEVER throw away an original Corvette part.
If nothing else, you're going to need the seals to put the new ones on. I usually try to match the original install as close as able.

You can try your way of painting the support, but they rust from the inside out. Don't do it halfway, because you already know how much time and effort it will be to pull it all out just to rehab/replace the core support.

The radiator shop won't paint the parts prior to assembly, and as Joe notes they won't do as nice of a job as you would.
Be sure they use your original upper and lower supports, as discussed previously.

That's a good rule. not sure I will keep ratty old seals once all is said and done..but again...a good rule. For sure will tell them to use upper/lower supports and tanks. I am gonna give it a go with refurbing the core support. If the rust removal stage changes my mind I will go repro.

If it goes good enough for now but issues emerge later I can always swap out for a repro one when I take the body off in a few years to restore the frame. I bias toward keeping original parts wherever possible. For this year I had only planned to get it running again after a 20 year nap...dealing primarily if not solely with things that HAD to be addressed.....Well we know how that goes. Too much corrosion in the rad to risk overheating the engine so need recore. And once the rad is out...cake to take out the support. And then need water pump...so off come the pulleys....etc etc. down into the rabbit hole...

Edit to add...Decided on Duplicolor Semi Gloss EDA160307 for the support. And Eastwood Radiator Black Gloss for the rad.

[James G.]

Re: Radiator & Support Finishing..and other Qs

Local shop Greenville Radiator did the 71 Ls5 AC radiator for another NCRS member here in Greenville SC.
Old time radiator guy I made sure that he kept the original rails - helped him with the removal and re-install, he is happy as a clam, but swears off AC big blocks! I believe he told me it was $600 could have been $800.

[Brad Hillhouse (37766)]

Re: Radiator & Support Finishing..and other Qs

Keith -

I didnt find it in the thread, but what is your radiator shop doing about the steel side brackets? No core manufacturer makes the correct ones, not anywhere close. The last time I checked Dewitts would not sell just the core only. Can your shop remove the steel side brackets and install them on the new core?

Brad Hillhouse

[Keith M.]

Re: Radiator & Support Finishing..and other Qs

Keith -

I didnt find it in the thread, but what is your radiator shop doing about the steel side brackets? No core manufacturer makes the correct ones, not anywhere close. The last time I checked Dewitts would not sell just the core only. Can your shop remove the steel side brackets and install them on the new core?

Brad Hillhouse

Hi Brad,
So a quick update before I answer that question...spoiler alert I don't really know. So I "was" planning to use a shop which happens to be 10 mins from home and seemed qualified based on a phone call. But when I went to bring the rad down on Friday...and talking to the shop owner who was not the gu I talked to on the phone...he seemed a little hesitant...especially when it comes to re-using the top and bottom bars. So I found a shop in OH an hour from home that as he said..."has a lot of experience with you picky Corvette guys"...I took that as a good thing. He is working with me to get it as I want it...which preserves as much as possible with a goal of judging in the future. We discussed re-using the upper and bottom bars...which means removing the ones that will come on the new core and soldering the old ones on after removing from the old rad. Issue is...hard do that without having some solder show through between the bars and fins. These are both specialized radiator shops.

As to your question(s) Brad...I "was" going to call Dewitts but never did cuz I found this place in Ohio first.....but AFAIK DEwitts only work with aluminum rads (mine is copper) AND they don't just sell cores outright...and also AFAIK don't offer a recore service. As to "steel side brackets"...i don't really know what those are...the components i know are the fins/tubes, side tanks, top and bottom bars, etc. What ARE "steel side brackets"??

Thanks,
Keith

[Keith M.]

Re: Radiator & Support Finishing..and other Qs

Local shop Greenville Radiator did the 71 Ls5 AC radiator for another NCRS member here in Greenville SC.
Old time radiator guy I made sure that he kept the original rails - helped him with the removal and re-install, he is happy as a clam, but swears off AC big blocks! I believe he told me it was $600 could have been $800.

How did the upper/lower bars/rails look afterward? Any solder showing or anything? Or did they come out looking like the original?

[James G.]

Re: Radiator & Support Finishing..and other Qs

Nothing showing that I noticed (and I am more than picky(ANAL)) when we re-installed it.

[Brad Hillhouse (37766)]

Re: Radiator & Support Finishing..and other Qs

As to your question(s) Brad...I "was" going to call Dewitts but never did cuz I found this place in Ohio first.....but AFAIK DEwitts only work with aluminum rads (mine is copper) AND they don't just sell cores outright...and also AFAIK don't offer a recore service. As to "steel side brackets"...i don't really know what those are...the components i know are the fins/tubes, side tanks, top and bottom bars, etc. What ARE "steel side brackets"??

Thanks,
Keith

The top and bottom bars is something you want to address with the shop. The "side brackets" is a term I use for the steel upper and lower "bars". In the old days, radiators were "down flow" design and there were steel "side brackets" soldered on each side that held the radiator together, and also bolted the radiator to the core support. With the advent of the cross flow radiator, there still needs to be steel reinforcements to hold the core together, and I still call them side brackets even though they are on the top and bottom instead of left and right. There may be a better term, this is what I have called them since I was a kid growing up in a 3 generation radiator shop.

Dewitts does still make a 67-68 copper brass radiator and its listed on their website, but that is not wide enough for your application. Its possible that they do not even make a post 68 copper brass radiator, easier to just sell their direct fit aluminum line. There is no aftermarket radiator core manufacturer that we have found that makes the correct rectangle and square punch outs in the top and bottom side brackets. Most are a different design "U channel" that is stronger, but completely different than the original Harrison design.

Brad Hillhouse