# TAB's DIY corner... Acrylic intake/spray bar, how too.



## TAB (Feb 7, 2009)

For the purposes of me writing this post I tried very hard to use the most common (and cheapest) tools I could come up with that would complete the project.

*Tools needed for this project:*

Hack saw with fine-toothed blade. (Table saw, chop saw, skill saw, dremel...)

1 metal hose clamp

Heat gun (bending strip is allot easier if you have one)

Drill

# 29 drill bit

8-32 tap

Tap holder.

Mil cut bastard file (dermel, table saw)

Small section of 2" abs pipe or other circler form.

Braided wire that can be used a mandrill.

Bucket of water

Grease pencil

*optional tools:*

Paint stir stick (yes really)

400 grit sand paper (peel and stick is best)

Flat surface for sand paper

Mapp torch (not propane, hydrogen is best,)

Masking tape

Pencil.

Novus plastic polishing kit.

* Materials needed:*

One 6' length of extruded acrylic tubing. (5/8" for the project I am showing, it will fit ehiems 16/22, tubing. Might want to buy two, so you can practice on one 1st)

1' of extrude acrylic rod (1/2" in this case as we are using 1/16" walled 5/8" tubing)

1 polystyrene, acrylic or nylon screw with 8-32 threads 3/8- 5/8" in length

2 hose clamps (plastic are best)

1' of 5/8" inside diameter vinyl tubing.

These materials can be found at tap plastics (.com) or your local plastic supplier.

On a scale of 1-5, this is about a 2 on the difficulty meter. Using a heat gun vs., my bending strip I found having a second person to hold the heat gun helpful, but not necessary.

Now that I have wet your appetite, I need to get back to work; I will finish this when I get home.


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## dj2606 (Oct 15, 2008)

Ew man, the humanity the humanity. I cannot wait


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## TAB (Feb 7, 2009)

So 1st things 1st. You need to come up with a plan that will work for _you_. Now this can be as simple as just thinking about it and doing some measuring. (Some people can do that, others can't.) I highly recommend you do a scale drawing (or at least close). It does not have to be fancy, but it does need to have all the info on it.

Here is an example:



















No comments about bad drawings... 

Before we get to bending, there are two things I would like to say. The use of a heat gun on flammable surfaces (like pictured) is dangerous, These things get hot, so have a fire extinguisher ready, just in case. If you actually got the plywood hot enough to burn, you're doing something wrong 

So here are the tools we will need (bucket of water not pictured) to make the 1st bend.










Resist the temptation to cut the piece to final length before you bend. Things don't always go as planed, and its allot better to waste 1 foot of something then it is to waste 4.

Start out by measuring and marking a small line on the tube at 5", 6", 12" and 13". The 1st mark and last mark are so you know how far to heat the tube. The 6" and 12" are _about_ where you want the bend to start and stop.

Take the mandrill, aka wire; place it in the bucket of water. This will allow for easier introduction, extraction and help prevent the jacket form sticking to the tube. Insert it into the acrylic tube about a inch past your 13" mark. With the heat gun set to 900 ish (high on most cheap models) and hold it 4-6" away. Move it back and forth between your heat marks while you rotate the tube. (This is where a 2nd person can come in handy.) Do this until the tube starts to bend under its own weight. Once this happens immediately place it on the table and bend it around the form. Do not force the tube to bend. If it does not want to go, keep the tube on the table and heat it just before the form so that it will bend. If the tube starts to flatten out or kink, that's ok, just gently press it down with your thumb (its hot so be careful.) What is important is that you keep it firm against the form. If it does not come out perfect the 1st time, don't worry; let it spring back and cool off, then try again.

Once you do get the tube bent to your liking, hold it firmly in place for 30 seconds after removing the heat gun. Now, while holding it firm, dunk it into the bucket of water for 10 seconds to set the form, but still warm to the touch so you can remove the wire. (Once again this is where two people will come in handy) if it does not want to come out, Reheat the tube slightly, it will expand and allow for extraction.

It should look something like this.










Now this is what it looks like if you try to bend it to far:










The good news is you can fix it by gentile heating and applying pressure with your thumb.

If you get the heat gun to close, or leave it in one place for too long, this is what happens:










You cannot fix this, you have litterly boiled acrylic, it will be very weak, might even leak and will be an algae magnet.

Now you can cut it to final length. Repeat the process for the return and the 90 degree bend.

On the 90 degree bend, if you find that you made the end a little out of round, don't worry, just heat the end, squeeze it, and insert the end of the solid rod into it.

Its been a long day, I'll write up the rest of this part tomarrow. Any questions up to now, please ask.

My writing skills have never been great, I can tell you exactly how I want things, ask me to write it down, it might as well be in another language. Now math on the other hand...


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## tefsom85 (Jan 27, 2007)

TAB said:


> My writing skills have never been great, I can tell you exactly how I want things, ask me to write it down, it might as well be in another language. Now math on the other hand...


Have to disagree TAB. You're doing quite well! Great explanations


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## TAB (Feb 7, 2009)

Now its time to cut the groves in the intake pipe.

For those of you with a table saw or a dremel, you can skip this next paragraph.

To cut the groves you will need you mil cut bastard file, masking tape, grease pencil and the metal hose clamp. Start out by wrapping the section of tube that is going to be grooved with the masking tape. Draw your first line 1" from the end of the tube, and then every 1/2" above that until you have 4 or 5 of them. Now take the hose clamp, slide it over the pipe and a line it when your mark, with the screw end where you want to make the cut. Holding the tube firmly against a solid surface, place the file against the hose clamp and resting on the tube. Slowly draw the file backwards, at the end of the stroke, lift the file from the tube and repeat. DO NOT GO BACK AND FORTH. Doing so with cause chips in the tube. You only need to go about a 1/4 of the way thru, going further will drastically weaken the tube.

Table saw guys, raise the blade up ~ 3/16, hold the tube with your Miter T. Dremel guys, get one of the fatter grinding wheels, use slow speeds and make your cut.

When you're done it should look something like this:










Now on to the removable plug.

This is what you will need to install it (minus the drill, drill press is preferred if you have one)










Start by insuring the end of the tube is free of chips, or burrs.

Install the rod into the tube, do not force it. If its really tight, use the heat gun on the end of the tube, insert the rod, twist it around and rock it back and forth to expand the tube. Now mark a line for your final cut dimension and for the hole. I recommend going ~ 1/8" further then the head of your screw.










Now using the #29 drill bit, drill your hole. Go very slow (<200 rpms) and apply very little pressure.

You know you have your speed and pressure correct when, you see spiral shavings coming from the flutes of the drill bit and they are growing. If you start to get a strong smell of plastic, or your seeing a bulged of clear plastic, your going to fast and/or applying too much pressure.

With the hole drilled, its time to tap. Now taping plastic is nothing like tapping metal, I mean nothing like it. For one, you generally have to tap it several times, the chips tend to stick to every thing and it's very easy to cross thread.

While firmly holding the tube against a hard surface. (Vice would be a good idea, but not needed) hold the tap as square as you can with the point inserted into the hole. The weight of the tap and handle is enough pressure. Slowly turn the handle clock wise, 2 turns. If you get out of square on these 1st full turns, that's fine, just back out and try again. After your in your 1st two turns, back out a half a turn. Then clockwise a half a turn, back a quarter, clockwise another half. Repeat this process until you have 5 complete turns in. Then completely back out the tap, clear the shavings from the tap and blow out the hole. Now reinsert the tap making sure to keep is square and you're in the threads you just cut. Go back down the 7 turns, and repeat as before.










After the 1st few 5 or so revolutions, you should be able to spin the tap with 1 finger. * IF AT ANY POINT YOU CANNOT DO THIS, BACK THE TAP OUT!!!!* other wise you risk cracking the tube, nothing is more frustrating then getting to the last step of a project only to break it. Continue with the tap until you reach the top of the teeth on the tap. Now here is where it different from metal. Flip the tube over and repeat the process from the other side. If you have ever done any tapping of metal, you will know that this is a big "no-no". Acrylic, more so when it's extruded, is funny, it tends to build up and hold on too static charges. Which makes taping it a real pain as the chips stick to the threads.

Blow out the hole now, test fit your screw, you should be able to turn it with your fingers. Make sure you take it all the way down to the head of the screw. If you cannot do this, remove the screw and guess what? Yep, run the tap down it again.










Cut thru both the tube and the rod to final size. Congrats you now have a completed intake tube.

Instructions on polishing will be at the end.

Up next, spray bar instructions/ tips.


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## TAB (Feb 7, 2009)

Now on to the spray bar.

This one is super easy. Start by pluging one end, doing the same drill and tap procedure as above.

Now mark lines on the tube every inch. drill holes at those marks using a ~ 1/8" drill bit( that number 29 will do fine)

It maybe helpful to build a fixture to hold the tube.

Here is the one I built just for this project.










its just a small bit of scrap ply wood I had laying around, some screws and lines drawn on it every inch.

What I did to make the holding "clamps" was drill a 5/8" hole in a small piece, then ran it thru the table saw at the middle of the cut.










For those of you that have a drill press, here is a trick that will make this repatative task alot easier.

take 2 clamps and a strait piece of wood and clamp it to the table of the drill press to work as a fence. Place a center line on to "fence" then all you have to do is hold the fixture to the fence, line up the marks and drill your holes.

Now onto polishing.

I've love to write a how to on this subject, but video is worth 10k words.

http://tapplastics.com/info/video_detail.php?vid=26&format=windowsmedia&

note you can't flame polish edge of the tube... it will catch fire and burn.


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## IbnOzn (Mar 16, 2007)

Great how to. I made a set of these myself a few months back that are very similar. To keep the tube from flattening as its bent I used a screen door spring attached to the end of a dowel with an eyescrew. The springs are 1/4" to 7/16" in diameter and around 8" long and can be found at Home Depot. 

Insert the spring once the tube is pliable and slowly back it out of the tube as you bend.


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## gillt (May 15, 2010)

One problem I encountered was in using the braided wire for the "U" bend. My wire was plastic coated and so it was impossible to remove from the pipe after bending. Do you use bare wire?


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## WeedCali (Mar 6, 2010)

Great idea!

but next time you wanna bend tubing like that, fill it with sand and i can guarantee you it wont kink


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## TAB (Feb 7, 2009)

gillt said:


> One problem I encountered was in using the braided wire for the "U" bend. My wire was plastic coated and so it was impossible to remove from the pipe after bending. Do you use bare wire?


Did you get it wet before you put it in? the wire I used was the in the pics.


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