I have been wanting to do this for some time now. I am sick of paying for injectors that either break or don't work quite the way I want them to so today after work I went to Home Depot to build myself an injector.
After an hour or so of testing fittings and some employees looking at me funny, I finally figured out everything I needed and brought it all home to be assembled.
Here is the cast.
1/2 Gallon Garden Sprayer $6.97
20" Faucet Supply Line. 3/8" female compression with rubber seal on one end, and regular 3/8" compression fitting on the other. $6.57
Brass Adapter Fitting. 3/8" compression on one side and 3/8" female flare thread on the other. Make sure you get the one with the FLARE threads and not the regular PIPE threads. They look almost the same but the pipe threads will not work. $4.40
OO 1/2" beveled faucet washers. You only need one, but they come in a 10 pack.$1.67
And finally you will need an injector needle. I tried both of these types and they both worked fine.
I already had these so they were free.
OK time to build!
First unscrew the nozzle from the pump sprayer. Note the white plastic piece inside the nozzle. We will call this part the nozzle seat. You will need to remove this and keep it. The sprayer will not be able to build pressure without it. The cone shaped part in the sprayer seats against the hole until you press the spray button.
To get it out unscrew the tip of the nozzle and remove the clear plastic piece inside like so.
Then use your needle or something else that will fit and push the nozzle seat out from the other side.
Now take the brass adapter fitting apart like so.
And put the nozzle seat into the female side EXACTLY the same way it was in the nozzle.
Now screw the brass fitting onto the sprayer where the nozzle was. It should be snug, but not super tight. The male threads are plastic, and might strip if you go too tight.
Now take the female end of the faucet hose and screw it onto the male end of the brass fitting. Hand tight should be good enough but hold a backup on the brass fitting so that you aren't tightening against the plastic threads.
Remove the compression nut and ferrule from the other end of the hose.
Now for the hardest part. Getting the needle ready to be installed.
Take the needle of your choice and one faucet washer, and push the washer onto the hub end of the needle. This is a very tight fit, but I found that using a clothespin as pictured below to push it downward helped. And obviously try not to stick yourself.
Now that you have the washer in place on the needle hub, all thats left is to take the compression nut from the faucet hose and use it to secure the needle onto the hose.
And now you have a fully assembled ready to use injector pump!
So now for the obvious question. Does it work? Well I haven't used it on a hunk of meat yet, but it looks like it will work fine. Yeah I probably could have bought one for not that much more than what I spent, but it was an easy fun project, that will hopefully end my injector searching.
I have taken so much info from this site, that I like to contribute what I can, when I can. This may not be much, but hopefully someone will find it useful.
Thanks for lookin!