I've got a Ford van I'm working on for a ministry I'm involved with. One issue I found was that the charcoal canister is missing and the vacuum lines were left unplugged. I know I could just plug the lines and call that good, which I will do if it comes to it, but I wondered if there was a way to build a replacement?

What I'm thinking is, a chunk of PVC pipe (3" or 3.5") with a cap on both ends with nipples for the vac lines and line from the fuel tank coming out of one end. One nipple would have a line extending further into the pipe to make sure the vapor from the fuel tank is getting absorbed by the charcoal. I'm sure this will hold vacuum great, but what I'm not sure on is what material to use for the "charcoal."

I thought about just using grill grade charcoal and crushing it, but I don't know how I would prevent the dust from getting sucked into the vac lines. I also don't know how much I would need to use.

Ideas/suggestions/fact-based data? Has anybody ever taken one apart?

Thank you.

 

Go to salvage yard and pull one. Probably be much cheaper in the long run.

 

You need stuff called "Activated Carbon"... usually comes in 50 or 100 pound sacks but I'm sure you could find smaller quantities if you looked hard enough.

 

You can buy small quantities of Activated Carbon (Charcoal) from a pet store. It's used as part of the filtering systems in aquariums. You will need to wash it to remove the dust and then let it dry. Perhaps put it in the oven overnight at a low temp. Handle it carefully after washing as it crumbles easily. Perhaps put it in a piece of nylon stocking that's been cut to length and tied off so you can put it inside your canister without breaking or crumbling it. I like the idea of PVC pipe as it's durable and not prone to rusting or cracking. Let is know how it turns out.

 

SteelHorse - I'm not against junk yard parts, and while the one I mainly do business with does have a 30 day warranty, I'm always skeptical because you just don't know what you're gonna get. The hassle of returning to the junk yard and exchanging parts, IMO, makes it not worth it in most cases. Particularly with something like the charcoal canister - this is a part/system that's often ignored or overlooked, so there's no telling what condition (internally) it might be in. I might go poking around to see what I can find, but I'd basically want it to be as close to brand new as possible before I'd purchase it.

On the activated carbon - does anybody know how much I would need to use? I'm good enough at math to calculate volume and percentages, so if I can get even a ratio of carbon to container volume (or the amount of carbon in ounces/grams/pounds/whatever) then I can figure out the rest.

I'm also wondering if maybe I need to find some kind of filter/screen to prevent any dust from moving through once it's been assembled? Ddaybc - I get your idea on the nylon stocking, but it seems to me that if the activated carbon is that fragile, it wouldn't take much bouncing around once on the road to turn it into a dust fine enough that it can slip through the stocking.

Is there another medium I could use in place of the activated carbon? I'm assuming they originally chose this b/c it's resistant to being broken down by gasoline, so if there's another material I could use to do this, maybe that's an option too.

Thanks again for all the suggestions - if I pursue this project, you'll be getting a write up.

 

This isn't your exact car obviously, but this should help you rebuild it. It's pretty easy stuff! I really like your idea of using PVC. Just make sure you're using chemical/fuel grade PVC, some plastics can be broken down by gasoline and you sure don't want that!

Rebuilding The Charcoal Canisters : How-To Library : The MG Experience

 

Not carbon volume vs. container volume, you're doing it backwards. First you figure out how much carbon you need to do the job, THEN you find a container big enough to contain it all.

You'd need data sheets for the carbon at a minimum, then you'd probably have to know how much vapor is actually there as well as how much carbon it would take to neutralize it.

What I would do if you really want to build your own, is go to a junkyard and get a carbon canister. Take it apart, weigh the carbon, and that should get you a fairly close estimate of the amount that you'll need in your new one.

 

Dixie460 is right. Really, I like the DIY in you or anyone, but realistically these are like $10 at the junkyard.

Given what's needed, the fuel to drive/spend, and the time involved, wouldn't it just be simpler to get a unit from the scrapyard?

 

Depending on the year of the Van you could buy one from $100 on Ebay to about $150 from an online parts store.

 

I looked up the canister size in my service manual. It shows two different sizes. One is 1400 ml and the other one is 925 ml. The diagram shows both filled completely with carbon. They have a foam filter and retaining screen at the inlet portion. That takes care of the concern about the fragile nature of the carbon.
The canisters are sometimes used in pairs when the vehicle has a large fuel tank or dual tanks. The implication is, use a much as you want, within reason. They are, after all, only storing fuel vapour until you start the engine again.
There are a few other structures inside the canisters shown that are not clear so I would cut my current canister in half and use it as a guide for building your new one.

 

I'll say it again. Junkyard. This discussion has been going on for a day and a half. It could have been fixed already. You can't use PVC around gas. It will break down the pipe itself and the glue. ABS is fine, but the glues are still susceptible to the gas. That's why they are welded together. Nothing against saving a few dollars, or improving something, but there are times when re-inventing the wheel is more costly and more expensive. Sorry if I'm being a downer to your quest, but I'm just trying to save you some failed attempts or possibly a fireball going down the road at 60. Gasoline itself is not very volatile, BUT the vapors ARE. Not worth the risk.

 

Thank you for the link.

SteelHorse, thanks for your concern. Seriously. This van will be carrying up to 15 kids and young adults at a time - I definitely do not want it bursting into flames while driving down the road, so I won't use PVC.

But let me clarify - I am not stuck on the idea of building this myself and that's the only option and it's just not going to happen any other way.

I have time - the canister is only 1 repair of several I am making to the van. I've had it in my driveway for 2 weeks and expect it to be there for another 2 weeks before I'm finished with everything and it's actually running again. So if, in that time, I find a reasonable way to build a canister for a reasonable price, that's what I'm looking to do. If not, no biggie, and I get one from the junkyard.

I also GEEK OUT on this *****! I love finding ways to innovate and build my own stuff - not so much trying to "reinvent the wheel" and more like "I'm gonna do this, because it's awesome and pass or fail, I want to try!" And when it's a pass, I get to share my experience (and photos!) with people on the internet. And that's just great, because my wife could care less how excited I am about this...

So, that said....

PVC won't work? Okay. Perhaps I look at copper, or maybe rigid conduit? I know there's a lot of rigid conduit fittings in various sizes, and they're already threaded on the ends, so maybe a rigid fitting and caps?

I'm also still curious if there's another medium that can be used besides activated carbon. I've no idea what... if the point is to absorb vapors and resist breaking down to gasoline, wouldn't floor dry just about have the same properties? Just kidding... or am I?