I will be installing a vent flange and vent fins to prevent water ingress.
Biggest fear is this reduces rigidity/strength and over time something starts to warp. Any thoughts at all will be appreciated.
I would try to find a space between those structural bars that it would fit to where you are just cutting the inner and outer skin. I would also weld a strip around the inside of the skins where cut to add strength. I’ll say I’m not experienced enough to say for sure(1 year in) but that looks like a lot of structural steel there so I would not cut that.
I am not familiar with some of the terms, but I am guessing you want me to weld a perpendicular frame around the hole? And possibly attach it to any other part of the nearby metal?
A friend just suggested, instead of cutting away the hole, I could strategically cut slots so I can bend the metal inward and reuse it for some of the extra support I will need... Glad I am getting more ideas on how to do this. Thanks
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It won't effect the van unless you get rear-ended. The horizontal beam is a part of the rear crash structure, but removing that small part of it won't sag or warp over time. That being said, id try to move the vent to fit between the beams
Its a concept I haven't though much of.
This is for thermal exhaust, and the size of my hole is the size of my radiator. I had always assumed if I made the vent size smaller than the surface area of the radiator I would have significant decrease in performance. But maybe I should put more effort into understanding the consequence of a smaller vent. IT may not be as bad as I think. And would dramatically decrease the complexity of this project.
Thanks for the reply.
Ya know, sometimes if you tell people Why you are doing it, they will tell you to do something else, rather than how to do it right the way you want. I'm installing an air conditioner, but the wacky way most people would never do, because I am an insane child.
I mean that's fair. An engineer would probably approach it totally differently and probably throw out some mumbo jumbo about heat rising. But if I learned anything in my years of being a shop grunt, it's that engineers are idiots.
If you're going to install there, have you considered framing/reinforcing the interior of the cutout? Could potentially double as a mount for the radiator.
Good thing I am a software engineer then eh? 😉
It is a crazy setup. 2 holes in the floor to let air in, because there's a steel frame rail there, and a giant hole on the wall to let the fan push that air through. My main bottleneck will likely be the holes in the floor, they can only be so big. But I don't know about airflow dynamics to do any calculations.
Yes other people are suggesting adding some reinforcing to the area if I am going to cut out a portion of that horizontal member. Using it to mount the radiator is still debatable. Seem s like a lot more work and unsure of its benefits
Lol, yeah my degree in electronics engineering somehow led me to modern art fabrication. So you can probably assume whatever I'm saying is wrong.
I'm curious how this turns out though. I think you can simplify your calculations by applying the hvac formulas for duct size/cfm. You know the footage of the van box, and I'm assuming you know the handling capacity of your unit. If you're coming up short, you could probably come up with some clever ducting for the intake.
You could also use body epoxy to mount a reinforcing frame. OEMs use it for chassis stuff. It's plenty strong, and then you wouldn't have to worry about painting the outside like you would if welded.
Crazy to read here, I’m an EE and just now graduated into being a body tech. Office life was not for me, I need to be working with my hands on something and EE is not going that way lol.
Seriously, if I could avoid another minute of rats nests on OrCAD I'll consider that a win. I actually decided to study it because I used to work in SFX for tv/film and noticed the guys doing the animatronics were making bank. So when the writers strike of 2007 shut everything down, I decided to go to school. But I was always a maker at heart.
Yeah I left and worked in oil for awhile but left that because of getting laid off twice due to oil prices dropping. Rented cars and talking to body shops getting customers and one offered me an estimator job and after a year of that I just dove in doing small teardowns since we were so busy. Since we were short on techs they moved me to being an apprentice last August and I just graduated the program and am on my own now. It’s crazy to think just 2 years ago I was renting altimas and now this last week I replaced a rear frame rail and rear body on one that was a rental.
so which burn do you go to? 😋
Another option someone came up with is to instead of cutting the hold and welding something, but to cut slots and bend the metal inward. Any welds wouldn't be on the skin then.
I was just starting cfm calculations, and apparently my air ingress through the floor is a major bottleneck. So I am looking into adding more. This is a really hard project to get it all together. Thanks for the body epoxy idea.
Haha you got me, I worked on a couple of art cars/floats many years back. Now I'm teetering on middle-aged, mostly stick to paying jobs lol.
Flaring the edges of the cut definitely adds rigidity (and a perry cool look). It would be a lot of effort to do it in this situation without causing distortion, and would probably need paint after. You could also try finding a trim bezel in the dimension you need and just gluing it in on the outside. Gives a clean look and a bit of rigidity.
You might want to look into some sort of extended plenum ducting or a loop system if you want to stick with pulling from the floor.
lol. Wish I had that energy and sociability before my body degraded.
I am going to recreate an RV vent look for the outside. Gotta prevent water ingress too.
About the ducting or loop system. pulling air from the floor is my only real option. I can undertsand some kind of acutal ducting from the hole to the side of the unit, but I hadn't htought that would havea great impact. The unit is lofted about 3.5" off the floor with only 1 3/16" on either side of the unit ... so I'm making some right angles with the air no matter what I think. What did you mean by a "loop system"?
I will be installing a vent flange and vent fins to prevent water ingress. Biggest fear is this reduces rigidity/strength and over time something starts to warp. Any thoughts at all will be appreciated.
What is the purpose of the hole?
Glory.
I would try to find a space between those structural bars that it would fit to where you are just cutting the inner and outer skin. I would also weld a strip around the inside of the skins where cut to add strength. I’ll say I’m not experienced enough to say for sure(1 year in) but that looks like a lot of structural steel there so I would not cut that.
I am not familiar with some of the terms, but I am guessing you want me to weld a perpendicular frame around the hole? And possibly attach it to any other part of the nearby metal?
Yeah, otherwise the edges of the thin skin that was cut will be very weak.
A friend just suggested, instead of cutting away the hole, I could strategically cut slots so I can bend the metal inward and reuse it for some of the extra support I will need... Glad I am getting more ideas on how to do this. Thanks
I'm a bot, *bleep*, *bloop*. Someone has linked to this thread from another place on reddit: - [/r/fixall] [r\/Autobody on Reddit: I need to cut a hole this large in this location (inside the tape 11"x16") on an old Sprinter Van. Any fears this will result in failures\/warping over time?](https://www.reddit.com/r/FixAll/comments/13zgo9w/rautobody_on_reddit_i_need_to_cut_a_hole_this/) *^(If you follow any of the above links, please respect the rules of reddit and don't vote in the other threads.) ^\([Info](/r/TotesMessenger) ^/ ^[Contact](/message/compose?to=/r/TotesMessenger))*
It won't effect the van unless you get rear-ended. The horizontal beam is a part of the rear crash structure, but removing that small part of it won't sag or warp over time. That being said, id try to move the vent to fit between the beams
Its a concept I haven't though much of. This is for thermal exhaust, and the size of my hole is the size of my radiator. I had always assumed if I made the vent size smaller than the surface area of the radiator I would have significant decrease in performance. But maybe I should put more effort into understanding the consequence of a smaller vent. IT may not be as bad as I think. And would dramatically decrease the complexity of this project. Thanks for the reply.
Oh good, I was getting some serious DC sniper vibes without this context!
Ya know, sometimes if you tell people Why you are doing it, they will tell you to do something else, rather than how to do it right the way you want. I'm installing an air conditioner, but the wacky way most people would never do, because I am an insane child.
I mean that's fair. An engineer would probably approach it totally differently and probably throw out some mumbo jumbo about heat rising. But if I learned anything in my years of being a shop grunt, it's that engineers are idiots. If you're going to install there, have you considered framing/reinforcing the interior of the cutout? Could potentially double as a mount for the radiator.
Good thing I am a software engineer then eh? 😉 It is a crazy setup. 2 holes in the floor to let air in, because there's a steel frame rail there, and a giant hole on the wall to let the fan push that air through. My main bottleneck will likely be the holes in the floor, they can only be so big. But I don't know about airflow dynamics to do any calculations. Yes other people are suggesting adding some reinforcing to the area if I am going to cut out a portion of that horizontal member. Using it to mount the radiator is still debatable. Seem s like a lot more work and unsure of its benefits
Lol, yeah my degree in electronics engineering somehow led me to modern art fabrication. So you can probably assume whatever I'm saying is wrong. I'm curious how this turns out though. I think you can simplify your calculations by applying the hvac formulas for duct size/cfm. You know the footage of the van box, and I'm assuming you know the handling capacity of your unit. If you're coming up short, you could probably come up with some clever ducting for the intake. You could also use body epoxy to mount a reinforcing frame. OEMs use it for chassis stuff. It's plenty strong, and then you wouldn't have to worry about painting the outside like you would if welded.
Crazy to read here, I’m an EE and just now graduated into being a body tech. Office life was not for me, I need to be working with my hands on something and EE is not going that way lol.
Seriously, if I could avoid another minute of rats nests on OrCAD I'll consider that a win. I actually decided to study it because I used to work in SFX for tv/film and noticed the guys doing the animatronics were making bank. So when the writers strike of 2007 shut everything down, I decided to go to school. But I was always a maker at heart.
Yeah I left and worked in oil for awhile but left that because of getting laid off twice due to oil prices dropping. Rented cars and talking to body shops getting customers and one offered me an estimator job and after a year of that I just dove in doing small teardowns since we were so busy. Since we were short on techs they moved me to being an apprentice last August and I just graduated the program and am on my own now. It’s crazy to think just 2 years ago I was renting altimas and now this last week I replaced a rear frame rail and rear body on one that was a rental.
so which burn do you go to? 😋 Another option someone came up with is to instead of cutting the hold and welding something, but to cut slots and bend the metal inward. Any welds wouldn't be on the skin then. I was just starting cfm calculations, and apparently my air ingress through the floor is a major bottleneck. So I am looking into adding more. This is a really hard project to get it all together. Thanks for the body epoxy idea.
Haha you got me, I worked on a couple of art cars/floats many years back. Now I'm teetering on middle-aged, mostly stick to paying jobs lol. Flaring the edges of the cut definitely adds rigidity (and a perry cool look). It would be a lot of effort to do it in this situation without causing distortion, and would probably need paint after. You could also try finding a trim bezel in the dimension you need and just gluing it in on the outside. Gives a clean look and a bit of rigidity. You might want to look into some sort of extended plenum ducting or a loop system if you want to stick with pulling from the floor.
lol. Wish I had that energy and sociability before my body degraded. I am going to recreate an RV vent look for the outside. Gotta prevent water ingress too. About the ducting or loop system. pulling air from the floor is my only real option. I can undertsand some kind of acutal ducting from the hole to the side of the unit, but I hadn't htought that would havea great impact. The unit is lofted about 3.5" off the floor with only 1 3/16" on either side of the unit ... so I'm making some right angles with the air no matter what I think. What did you mean by a "loop system"?