My Version of a Bazooka Screen

Sunday, April 08, 2007

My Version of a Bazooka Screen

Okay, so this is something I have thought about doing for quite some time and am only now getting to it so here we go:

Not too long ago I built my first mash-tun out of a cooler and have been using it ever since. However, my first few batches had some problems because I used a filter I found in this website that was the basis for my mash-tun. You see, the filter that he used and what I was able to find had to be different. Mine was a water connection hose braid, however it was flimsy like cloth and could not hold up so it was giving me a really slow flow. His sounded like a more sturdy hose braid that could be crimped at the end.

After reading Grove's Beer Log about his new mash-tun and the Bazooka Screen he bought, I was inspired. I went out to home depot and bought some window screen and started to work...this is what I came up with.

The screen was in the window section at Home Depot and is was $6 for a lot of it. The good part about buying extra is that I can make other screens if need be. I sized up the length that I would need for it and cut the piece.

I rolled the screen around a small piece of PVC that I had, it was about 1/2" diameter. After I rolled this around the PVC a few times, I pulled the PVC out and picked the size I was going to make the screen. From there I left about 2" on both the beginning and the end of the price of screen and bent it over once to start to make a seem. I used pliers to pinch the seem down. I repeated this process of bending and crimping until I had the screen at the size I wanted. It wound up being about 3 good bends and I cut off all the excess.

From there I slid the screen onto a barbed copper fitting (something most people who have a home brew system are probably familiar with) and affixed it with a small screw-tight clamp.

*as you will note, I cut very small pieces of the PVC and slid them into the screen to reinforce them and act like ribs, I am not sure how much this really helps, but it doesn't hurt.

From here I cut the filter to length and crimped the end the same way that I crimped the edge, by folding and clamping.

In the end, the whole process was only about 1/2 hr of work and because I had some of the extra parts lying around it only cost $6 for the screen (which I still have about 90% of). If anyone were to do this, I would recommend a good pair of gloves and a place that you don't have to worry about making a mess of. Those little wires poke the hell out of your hands and get everywhere. Otherwise it's cake.
Good luck, cheers!


Ted Danyluk said...

That looks like a worthwhile project. I use a Phils false bottom with one slight modification and have had no problems and don't plan to change anything. But I was curious about your homemade bazooka screen.

It seems as though it wouldn't hold up to the weight of the grain. Have you experienced those PVC rings falling down sideways? Is it difficult to clean?

I have one bigger question in regards to these "tube" types of screens. I was also wondering if your club brought this up at the meeting about sparging. Does the liquid only/mostly exit right at the point where the the tube is fastened onto the port-hole? If so, would that cause inefficiency in the sparge flow?

It seems that a false bottom allows the liquid to evenly fall through the entire bottom before it exits through the outflow tube.

Its always been a big curiosity for me.

Travis said...

Good question!

First off, the PVC rings fall sideways and off kilter, but in the end they are still helping to maintain some semblance of a tube form. With that said, I thought it was a weird idea at first, but it's actually worked out a lot better than I ever anticipated.

Regarding the tube versus the false bottom, there was not any conversation about that at my meeting, but here are my thoughts on it:

From what I have seen, the liquid does favor the front exit point where the greatest suction exists, but as the grains thicken up in that area, a more solid tube is created and the suction point moves back. I would say that when you sparge with a tube screen, you would have to do a lot of mixing and you would find that you favor the spout side because that's where the action is. But when things get thick suction moves more to the middle.

Again that's just my observation, but it looks like that's what is going on.

Thanks for the quesion, cheers!