Hood Bubbling
Race Director
Joined: Nov 2006
Posts: 13,151
Likes: 7,765
From: Sunshine Coast, Queensland, Australia
2025 C3 of the Year Finalist - Modified
2024 C3 of the Year Finalist- Modified
2022 C3 of the Year Finalist - Modified
Cruise-In VIII Veteran
Not thinking it's anything to do with a heat shield or heat. I've never run any kind of heat shield or hood blanket.
Blistering paint is generally poor prep work before paint now outgassing. Also oil soaking up from underneath can cause issues. A blown air conditioning compressor seal can spray oil on the underside of the hood as an example. This will soak through and create paint issues.
The joys of fibreglass!
Posting up some clear pictures of the problem could help. Or, everyone can continue to just guess.
Blistering paint is generally poor prep work before paint now outgassing. Also oil soaking up from underneath can cause issues. A blown air conditioning compressor seal can spray oil on the underside of the hood as an example. This will soak through and create paint issues.
The joys of fibreglass!
Posting up some clear pictures of the problem could help. Or, everyone can continue to just guess.
Race Director
Joined: Nov 2006
Posts: 13,151
Likes: 7,765
From: Sunshine Coast, Queensland, Australia
2025 C3 of the Year Finalist - Modified
2024 C3 of the Year Finalist- Modified
2022 C3 of the Year Finalist - Modified
Cruise-In VIII Veteran
Oh, and what to do about it.
If it's oil soaked, get a new hood.
If it's outgassing. Strip back to bare glass. Redo.
If it's oil soaked, get a new hood.
If it's outgassing. Strip back to bare glass. Redo.
Le Mans Master
Joined: Aug 2005
Posts: 6,513
Likes: 1,949
From: Temple Terrace Florida
As our Aussie member said, most likely from a bad AC seal. Where on the hood are the bubbles? If it's over the AC compressor, you have your answer. A few companies make shields to prevent this from happening. Jerry
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,809
From: Cool Northern Michigan
Actually, it's not a heat shield at all.
As we all know, the small confines of a C3 engine bay certainly do not need a hood blanket to keep it warm. Nor does the hood paint need protection.
As the story goes, back in the early 70s when potential customers test drove a brand-new Vette, their lame complaint was that of: "Too Much Engine Noise".
So, the engineers sharpened their pencils and came up with a Sound Deadener.
Imagine that. A sportscar with extra noise. Not muffler. Engine noise.
So, whatever you want to call it, blanket, liner, insulation or deadener, it still contains the heat in the engine bay.
Most of them have been wisely removed over the years.
And there is a myth that the liner is to smother an engine fire. (Actually, it burns really well)
As we all know, the small confines of a C3 engine bay certainly do not need a hood blanket to keep it warm. Nor does the hood paint need protection.
As the story goes, back in the early 70s when potential customers test drove a brand-new Vette, their lame complaint was that of: "Too Much Engine Noise".
So, the engineers sharpened their pencils and came up with a Sound Deadener.
Imagine that. A sportscar with extra noise. Not muffler. Engine noise.
So, whatever you want to call it, blanket, liner, insulation or deadener, it still contains the heat in the engine bay.
Most of them have been wisely removed over the years.
And there is a myth that the liner is to smother an engine fire. (Actually, it burns really well)
Last edited by HeadsU.P.; Oct 13, 2024 at 09:00 PM.
Instructor
Joined: Oct 2021
Posts: 209
Likes: 33
Just had mine re painted because of same issue. Few things cause it, but only if its been re painted. Most common is to repaint in modern paint without removing all the old paint. These were originally lacquer and ya cant paint over it without using lacquer. Second is bad prep work or not clean when painted and primed. Third is tarping. If the paint is under a year old and you put a tarp over it, it will bubble. Shop that re painted mine went right down to fiberglass, then used modern materials. The warranty clearly says void if tarped for any reason. Car covers permitted only in dry storage, never outside, especially if it rains.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski