how to build an acid resistant hood & scrubber _hood_

[eeTHr]

golddie---

Here is a suggestion: Turn your system on, put a small Corningware casserole dish, about 6" x 6", in there, and pour about 1/4 inch of HCl into it. Open the HCl inside the hood, and re-cap it inside the hood.

If you don't smell anything at this point, it's sucking air pretty good.

Walk down wind of your exhaust. If you don't smell anything, the neighbors won't either. Either you are scrubbing most everything out of the hood air, or it's dissapating in the outside air.

A further test would be to add about a teaspoonfull of nitric to the HCl, opening and closing the nitric container inside the hood. Do the smell tests again.

Put a small piece of base metal into the casserole. Do the smell tests again.

Heat the casserole in the hood. Do the smell tests again.

This should give a good indication, with relatively little risk.

If you reeeeeealy want to know how much scrubbing you've got, tape or hold a litmus strip at the exhaust opening for 60 seconds, and see what it does. I don't know how to interpret that into ppm or anything, but it would give you some general idea.

Unless you will have the EPA testing it, the amount of reduction of fumes you need is up to you and your neighbors sense of smell, and the surrounding metallic property.

That's just my opinion, though.

 

[KEV2MO]

You can also have a coating, in a variety of plastics, "chopped" on. The last time I had a hood coated, I found a local guy with the equipment that made tornado shelters. He "chopped" on a coating of PVC fairly inexpensively. I also used the same PVC coating on wooden silver cells with great success.

I don't know exactly how these "choppers" work. I think it is molten plastic, chopped into small increments by a "chopper" gun and sprayed on. No solvents are involved. Maybe, bed liners are applied the same way.

Once, I had a 12' long hood made from bare plywood and I used it for about 5 years with no noticeable deterioration. I used two fair sized belt-driven squirrel cage blowers, in tandem, run off the same motor. The motor sat on top of the hood. I never, never incinerated in that hood and never had any problems.

YEH , I KNOW , HOW ABOUT THE ONE I JUST BUILT YOU ! THINK IT WILL LAST ? KEV

 

[golddie]

Hi Folks
I purchased one of these for 270 dollars and I see that the guy over charged me for it and on top of that the pump is too weak for this job, I will call him tomorrow and try to change it
He had told me that he does not do exchanges when I bought it
Am I doing something wrong is this pump the right size
March Pump
AC-3CP-MD
http://www.electricmotorwarehouse.com/march_pump/series_3_march_pumps.htm
http://www.marchpump.com/documents/Part%20Sheets/3-Series/0130-0032-1000.pdf

 

[Barren Realms 007]

Hi Folks
I purchased one of these for 270 dollars and I see that the guy over charged me for it and on top of that the pump is too weak for this job, I will call him tomorrow and try to change it
He had told me that he does not do exchanges when I bought it
Am I doing something wrong is this pump the right size
March Pump
AC-3CP-MD
http://www.electricmotorwarehouse.com/march_pump/series_3_march_pumps.htm
http://www.marchpump.com/documents/Part%20Sheets/3-Series/0130-0032-1000.pdf

What do you mean by too weak? Have you got a picture of what conditions the pump is running under?
If your pump has to pull the fluid up from a low place that will effect the flow rate. If it has to pump up to a high point or a long distance that will effect the flow rate. The inlet for the pump is 3/4" if you have reduced the inlet down to 1/2" pipe that will efeect the flow rate. The pump shows a 1/2" discharge. If you increase your discharge pipe to 3/4" this might help some. Need a little more info and picture if possible.

 

[golddie]

Hi Barren
Thanks for your help
I have made a system like the one 4metals designed
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=40&t=4776
I don't have pictures today but I will explain it a bit
From the spray nozzle I am not getting a spray and all I am getting is drips of water running
The flow of the drip is not light but it also is not very fast.
The bucket I am using is something I got from wall mart and its about 3 feet by 3 feet
The tank I have is very high so the pipe has to go up about 6-8 feet high than go forward 6-7 feet and like I said
its similar to that on the first page of that thread
Also I have to check to see if I reduced the pipe dimension but I think they are
Inlet: 3/4" FPT
Outlet: 1/2" MPT

 

[Barren Realms 007]

AHH ok this is for your scrubber. Is there any media for the scrubber in the container that you are pumping out of? Your piping should not be a problem. Sounds like either you have and obstruction in the pipe that you are pumping out of or maybe your pump is not primed. You might want to put a screen over the opening of the suction pipe and put a check valve on the sucton line so your pump will stay primed. I am going to assume that you got the 110V model and that the motor is not reversable. Check your instructions and make shure this is a 110V motor only, if the motor can be run in 110V or 220V then you might want to take the back plate off and make shure it is wired for 110V.

 

[golddie]

Hi Barren
Thanks for your help
This scrubber I have built has a few flaws and the reason is because I of me.
There is the problem with the pump and on top of that I goofed when making one of the holes
If you look in the picture you can see what I mean.
Right now I am not in my shop so I cant go to the scrubber to see things
First I will talk about the pump
From what I understand you say the pump should be primed
That is something I will do
In the picture I have written
I do not have a valve here
I will put a valve there and how fine should the screen be that is place

put a screen over the opening of the suction pipe

Once I try these things than I will know whether to play around with the motor

Now for my problem with the leak
I had a simple attachment part that I bought from my local hardware to fit into that hole
This would have been perfect

I decided to get something better and I bought an attachment that was better and with a bigger hole
for the 3 inch pipe
I had to get a pipe reducer for this thing and I had to make a bigger hole

The problem is I didn't glue this thing because there was a rubber in between the attachment and that tank
and this attachment has something where you can screw in a bolt from the inside of the tank
but the tank is too big and the hole on top is too small for me to go in there
so I just put that attachments in there without glue.

Yesterday I filled that tank with water and it started to leak
How can I fix this mess.
I have some silicon caulking but I think I would need something better than that like glue
I have the 3 different glues fo plumbing pipe
the gray ,yellow and white.
I am thinking of gluing the fitting attachment that has rubber in between
Can I glue the rubber with one of these glues
I am thinking of gluing the rubber the to attachment and than glue that to the tank
http://img259.imageshack.us/i/hoodandscrubber00116222.jpg/
Thanks again

 

[Barren Realms 007]

Hi Barren
Thanks for your help
This scrubber I have built has a few flaws and the reason is because I of me.
There is the problem with the pump and on top of that I goofed when making one of the holes
If you look in the picture you can see what I mean.
Right now I am not in my shop so I cant go to the scrubber to see things
First I will talk about the pump
From what I understand you say the pump should be primed
That is something I will do
In the picture I have written
I do not have a valve here
I will put a valve there and how fine should the screen be that is place

put a screen over the opening of the suction pipe

Once I try these things than I will know whether to play around with the motor

Now for my problem with the leak
I had a simple attachment part that I bought from my local hardware to fit into that hole
This would have been perfect

I decided to get something better and I bought an attachment that was better and with a bigger hole
for the 3 inch pipe
I had to get a pipe reducer for this thing and I had to make a bigger hole

The problem is I didn't glue this thing because there was a rubber in between the attachment and that tank
and this attachment has something where you can screw in a bolt from the inside of the tank
but the tank is too big and the hole on top is too small for me to go in there
so I just put that attachments in there without glue.

Yesterday I filled that tank with water and it started to leak
How can I fix this mess.
I have some silicon caulking but I think I would need something better than that like glue
I have the 3 different glues fo plumbing pipe
the gray ,yellow and white.
I am thinking of gluing the fitting attachment that has rubber in between
Can I glue the rubber with one of these glues
I am thinking of gluing the rubber the to attachment and than glue that to the tank
http://img259.imageshack.us/i/hoodandscrubber00116222.jpg/
Thanks again

I will start from the left of your picture and go to the right.

Question: What kind of material is your stack the the pipe from your fume hood connects to? If it is a pipe then the best way to fix that problem is to get a Tee and install on the bottom of the stack so you can glue your pipe from the fume hood into the stack. When you do this check with a plumbing supply house and ask for a FERNCO coupling to connect your pipe from the fume hood to the stack. This will allow you to service the stack in the future. If your stack is a square container then the best bet might be to fiberglass a small piece of pipe on to the stack and then connect your pipe from the fume hood to the stack. If you have never done fiberglass work it would be best to get someone that does this for a job because it is not someting for a novice to do. If you try to silicone it in it will not last and you will be back doing it again in the future.

Now between the stack and the tank your pump hooks up to you say you have a vlave to adjust the flow. You don't want to adjust the flow of water this way because if your pump runs dry it can over heat and burn it up. You want to adjust your flow of fluid by the vlave on top of the pump in your picture going up to your stack. This might also be why you are not able to pump fluid to the stack. You want to adjust your flow on the exit side of your pump so it does not loose prime on the pump. The screen should have holes no larger that 1/8".

You would be better suited having the stack drain into the holding tank from to top of the holding tank it makes servicing easier and there will be less problems with leaking in the future. But you have already got this built so you can work around it.

If you have to rework this or for future reference it would be better if your suction pipe from your pump goes down thru the top of your holding tank so you don't have problems in the future. You can do this by building a platform for your pump that sits higher than your tank. You will have less problems with a setup like this than trying to tap into the side of the tank anf ind a gasket that will work.

Your glues: Grey is for SCH80 pipe but it will work with other piping as well, The yellow glue is best for CPVC piping but it will work on other piping as well, Your white actualy it is refered to as clear glue is best for use on most all white piping. If you want strength get some blue blue for use in your white piping because it can be used even if the pipe joint has water on it and it will still set up and hold. Make shure you use cleaner when you are glueing you pipes together. Make shure you use enough glue and cleaner to get a good coat on what you are working on. And use the glue and cleaner on both pieces you are gluing together.

A few pictures would help to guide you better so I can see what kind of material you are working with.

 

[golddie]

Hi Barren
The tank is polyethylene and round tube

the pipe from the fume hood is black plumbing pipe I think its called pvc

and the fitting to connect the together is gray colored plumbing part
http://www.google.com/imgres?imgurl=http://uscorp.thomasnet.com/ImgMedium/Heavy-Duty-Bulkhead-Fitting.gif&imgrefurl=http://forums.gardenweb.com/forums/load/hydro/msg0120132712710.html&usg=__dKL5sPt5maw5ZdhuQVUZAtpTVaQ=&h=200&w=187&sz=35&hl=en&start=0&zoom=1&tbnid=4HrrKPUhUmetFM:&tbnh=136&tbnw=127&prev=/images%3Fq%3Dheavy%2Bduty%2Bbulk%2Bhead%2Bfitting%26hl%3Den%26biw%3D1024%26bih%3D578%26gbv%3D2%26tbs%3Disch:1&itbs=1&iact=rc&dur=474&ei=nJwkTdWDLpKenwfr9szqDQ&oei=nJwkTdWDLpKenwfr9szqDQ&esq=1&page=1&ndsp=15&ved=1t:429,r:7,s:0&tx=84&ty=84
looks like this

Also I didn't understand why I should have Tee instead of what I have now

I will answer your other questions later
Thanks very much

 

[Barren Realms 007]

Hi Barren
The tank is polyethylene and round tube

the pipe from the fume hood is black plumbing pipe I think its called pvc

and the fitting to connect the together is gray colored plumbing part
http://www.google.com/imgres?imgurl=http://uscorp.thomasnet.com/ImgMedium/Heavy-Duty-Bulkhead-Fitting.gif&imgrefurl=http://forums.gardenweb.com/forums/load/hydro/msg0120132712710.html&usg=__dKL5sPt5maw5ZdhuQVUZAtpTVaQ=&h=200&w=187&sz=35&hl=en&start=0&zoom=1&tbnid=4HrrKPUhUmetFM:&tbnh=136&tbnw=127&prev=/images%3Fq%3Dheavy%2Bduty%2Bbulk%2Bhead%2Bfitting%26hl%3Den%26biw%3D1024%26bih%3D578%26gbv%3D2%26tbs%3Disch:1&itbs=1&iact=rc&dur=474&ei=nJwkTdWDLpKenwfr9szqDQ&oei=nJwkTdWDLpKenwfr9szqDQ&esq=1&page=1&ndsp=15&ved=1t:429,r:7,s:0&tx=84&ty=84
looks like this

Also I didn't understand why I should have Tee instead of what I have now

I will answer your other questions later
Thanks very much

Yes the black pipe is called PVC. It is best to keep your piping the same kind if you can makes using parts easier and you don't have to keep different glues and cleaners around. Keep It Simple.
The grey part you are showing is a bung hole adapter. You can try and find somone that can weld plastic and attch it to your stck that way and you will be ok for future use with no problem. If this is the type of fitting you are using you can do without the tee. A tee for pipine in a situation like you are building is easier in th elong run to work with because you can glue it and not have to have special work.

 

[golddie]

I just went to my local hardware and they suggested contact cement or water proof epoxy
so I bought marine epoxy where you mix 2 different pastes to make the glue it comes in a syringe

 

[Barren Realms 007]

I just went to my local hardware and they suggested contact cement or water proof epoxy
so I bought marine epoxy where you mix 2 different pastes to make the glue it comes in a syringe

You can try it and see if it holds and I hope it does. I'm just letting you know what I have had to do in the past to make a situation like this work.

 

[golddie]

Hi Barren
I hear what you are saying the glue is going to come loose sooner or later
Here I saw how they did plastic welding
http://www.youtube.com/watch?v=UNa3Txagma0&feature=related
it looks like a gun of some sort
where would I be able to fin something like this locally

How about this as an idea
glue it fist and than weld it with plastic because the welding is only done around the edges


http://www.youtube.com/watch?v=NuA6d49Z7Rc&feature=related
This is another idea
but these are only around the edges and not the whole surface area of the pieace


That is what i might do glue it for now with epoxy and than buy a kit for welding plastic
Thanks

 

[Barren Realms 007]

Yea you can try to glue it for now and see if it will hold long enough for you to find the tool to weld it with. Be sure and leave the gasket out because the glue or the welding will not stick to it. The welder I used was only about the size of the silver part in the 1st video and it uses argon gas if I remember right with it. The heated gas will help heat up the material you are welding and it also acts as a shield but I don't remember from what. I don't know if grainger will have anthing like this but you can look thru them or your local welder supply, but if that gets you no where find a company in your area that works with plastic and they might be able to guide you on where to go.

 

[golddie]

Hi Barren
With the gasket I dont think I will be able to weld it so I will have to do one or the other
Here is a kit I wonder if it will do the job
DIY Plastic Tank Repair Kit LD35W
http://www.northwestpolymers.ca/welders.html

 

[Barren Realms 007]

Yea leave the gasket out, the only time you will use the gasket is when you tighten the retaining nut on the inside. The gasket will not adhere to the glue or the welded seam.

I don't see why that kit would not work for what you are doing. For the cost I would say give it a try. But when you get it prctice with it before you weld the bung hole in so you know what it will do. If you can find some plastic tank to tear apart and practice on you will be able to see what you will need to do to make the seam sold and fuse the parts together.

 

[golddie]

I have another idea but I have never done something like this before
I could take a torch melt the surface on the piece that i want to weld and melt the surface of the area where the piece will go and stick them together.

 

[Barren Realms 007]

I have another idea but I have never done something like this before
I could take a torch melt the surface on the piece that i want to weld and melt the surface of the area where the piece will go and stick them together.

NO, NO, NO, NO. Very bad idea. A tourh will carbonize the plastic and then it will defilnety not stick togather and you can throw the tank away. Only process like this I know if is similar to piping where a metal plate heats up the plastic while it is in a cradel, it heats up both pieces at the same time and then the plate is removed and the pieces are squezed together while they are in a cradle. This is done with piping like gas pipe under ground. I have a system like this and you can't duplicate this with a tourch.

 

[qst42know]

No glue will last on polyethylene.

Polyethylene cannot be welded to PVC.

Bulk head fittings are made to install on near flat surfaces. You may be able to compensate for your tank radius and make a seal by using two gaskets one inside and one outside. Do not over tighten the bulk head fitting or you will squeeze the gasket out of place.

If you can't get two gaskets to seal you might try heating your PE tank with a heat gun and pressing to produce a suitable flat area for the bulk head fitting.

 

[golddie]

Hi qst42know
I am not at my shop now and I had been thinking about what you said yesterday the tank is round and the piece is flat and will be a problem and I cant go inside the tank.

Even if I made the surface of the tank flat in that area what good is that going to do me
If I cant weld it and if I glue it the epoxy glue will last for a while but eventually it is going to come apart

Would thermoplastic welding be the same as the welding we were talking about before