Hi all. I built an underhood fuel surge tank using 5356 because it needs to be anodized. Then I happened upon 5356s potential for failure at temps over 150⁰. Would the anodizing process help prevent any type of stress cracking or weld failure with this or would I just start over with a different filler?
- Attachments
-
- 20210505_223058.jpg (47.38 KiB) Viewed 1906 times
I can't imagine the fuel would be at a temp of 150* nor the ambient temp under the hood be that high... But I also don't think anodizing is going to make the part more "heat resistant". Run it as is and determine whether it holds up. If it does, then you can proceed with anodizing for your aesthetic preference.
I prefer 4943 wire for anodized parts and higher temp applications.
I prefer 4943 wire for anodized parts and higher temp applications.
If it's not super close to the engine block, and isn't in the air path of a bunch of turbos, I'd say you're fine. Engine bay temps don't typically get anywhere near 150. the engine itself will have parts at 210 or so, but it's not like it heats the surroundings to that temp. I think they say temps are generally 25f above ambient. Think about it, have you ever opened a hood and were blasted back because it was too hot to be near? If not, it wasn't anywhere near 150.
Take a temp gun (IR) and shoot it around the engine bay after running a while. I think you'll find you can touch virtually everything that isn't connected to the engine, which would mean 125 or less.
As to the anodizing and cracking, it's really hard to say. You can google up any issue and you'll find hits, but that doesn't mean the situations apply to everything. People have been using aluminum anodized parts under hood for eons, and there's no issue with it. Most especially in racing where if there was a better way, they'd do it, aesthetics be damned.
another process you might consider is alodine. It's cheaper than anodize, doesn't penetrate as deep, and basically acts as a primer for paint. Doesn't require quite as much equipment to do the process, and isn't as hazardous. I've had customers ask for it years ago. The things come back sort of a light gold color, at least where we sent them. Now, you'd still paint the item, I don't think it's available in colors, but it doesn't harden the surface quite like anodize, so that might help with the thermal cracking (I'm a bit skeptical of how widespread the cracking is).
Take a temp gun (IR) and shoot it around the engine bay after running a while. I think you'll find you can touch virtually everything that isn't connected to the engine, which would mean 125 or less.
As to the anodizing and cracking, it's really hard to say. You can google up any issue and you'll find hits, but that doesn't mean the situations apply to everything. People have been using aluminum anodized parts under hood for eons, and there's no issue with it. Most especially in racing where if there was a better way, they'd do it, aesthetics be damned.
another process you might consider is alodine. It's cheaper than anodize, doesn't penetrate as deep, and basically acts as a primer for paint. Doesn't require quite as much equipment to do the process, and isn't as hazardous. I've had customers ask for it years ago. The things come back sort of a light gold color, at least where we sent them. Now, you'd still paint the item, I don't think it's available in colors, but it doesn't harden the surface quite like anodize, so that might help with the thermal cracking (I'm a bit skeptical of how widespread the cracking is).
Ehh there's been some vehicles that have rolled through our shop when we pop the hood in summer it is quiiite toasty under the hood .
Usually it's a old hopped up classic with poor venting / heat isolation on parts compared to a modern car.
Could always take remote thermostat and pop it under the hood to see what your underhood temps are like
Best thing I can think of if your concerned about heat would be a ceramic type coating like what they use on manifold headers to keep the heat inside of them.
Sent from my Pixel 3a using Tapatalk
Usually it's a old hopped up classic with poor venting / heat isolation on parts compared to a modern car.
Could always take remote thermostat and pop it under the hood to see what your underhood temps are like
Best thing I can think of if your concerned about heat would be a ceramic type coating like what they use on manifold headers to keep the heat inside of them.
Sent from my Pixel 3a using Tapatalk
kiwi2wheels
- kiwi2wheels
-
Ace
-
Posts:
-
Joined:Sun Feb 17, 2013 10:27 am
Big D posted this, re the 5356 / 150F, re the heat question of the very trick turbo installation he constructed.
http://forum.weldingtipsandtricks.com/v ... 8&start=40
From the same author ;
https://www.thefabricator.com/thewelder ... and-alloys
http://forum.weldingtipsandtricks.com/v ... 8&start=40
From the same author ;
https://www.thefabricator.com/thewelder ... and-alloys
I think you’re doing the right thing by holding off. After 25 years of making a living under the hood of a car, I wouldn’t doubt that in the right situations especially during the summer time ( depending on your location) that everything under the hood could be in excess of 150 degrees Fahrenheit. Just my .02 though. It does make me curious though. I might start taking random readings with an infrared temp gun just so I know.
Sent from my iPhone using Tapatalk
Sent from my iPhone using Tapatalk
Engine temps can easily be above 150. On a 60F day my transmission temp is 140F. The whole point of your radiator cooling system cap is that it is spring loaded. This allows the pressure to be above atmospheric when it gets hot to keep the water from boiling. Boiling water at atmospheric pressure is 212F. At any pressure above atmospheric it boils at a higher temp.
https://www.jbtools.com/blog/the-import ... ould-know/
At 10 psi water boils at 240F
https://askinglot.com/what-temp-does-wa ... -at-15-psi
So even with a standard temp difference of 25F on a heat exchanger ( radiators are heat exchangers) that puts engine temps at 200F easy.
https://www.jbtools.com/blog/the-import ... ould-know/
At 10 psi water boils at 240F
https://askinglot.com/what-temp-does-wa ... -at-15-psi
So even with a standard temp difference of 25F on a heat exchanger ( radiators are heat exchangers) that puts engine temps at 200F easy.
I have more questions than answers
Josh
Josh
I shot my LS7 the other day and on an 80-degree day I couldn't find anything over about 130 without pointing directly at an engine part. And I left it sit and soak for a few minutes in the garage to try to heat things up.walz10 wrote:I think you’re doing the right thing by holding off. After 25 years of making a living under the hood of a car, I wouldn’t doubt that in the right situations especially during the summer time ( depending on your location) that everything under the hood could be in excess of 150 degrees Fahrenheit. Just my .02 though. It does make me curious though. I might start taking random readings with an infrared temp gun just so I know.
Sent from my iPhone using Tapatalk
I think this highlights the point. Exhaust temps, IE the pipe will easily be over 150.BugHunter wrote:I shot my LS7 the other day and on an 80-degree day I couldn't find anything over about 130 without pointing directly at an engine part. And I left it sit and soak for a few minutes in the garage to try to heat things up.walz10 wrote:I think you’re doing the right thing by holding off. After 25 years of making a living under the hood of a car, I wouldn’t doubt that in the right situations especially during the summer time ( depending on your location) that everything under the hood could be in excess of 150 degrees Fahrenheit. Just my .02 though. It does make me curious though. I might start taking random readings with an infrared temp gun just so I know.
Sent from my iPhone using Tapatalk
I have more questions than answers
Josh
Josh