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Paul Covert
Posted: Oct 17, 2010 09:54 PM
Scratches in Mixing Chamber
For the past two weeks, I have been getting scratches in the surfaces of the mixing chamber and the side port (Fusion gun). This is happening only on the poly side of the gun. After about 2 hours of spraying, the gradual leak-by of the liquid causes the gun to clog.
I spray 1/2 pound foam. I suspect that I got a batch of material with some contamination that is causing this issue.
Have any of you had this happen before?
Posted: Oct 17, 2010 10:03 PM
All of the time!


Ssshhhh, don't tell Graco because they will tell you that they are precision milled parts that should never be tampered with.

Everytime I clean my spray chambers, side seals and inserts, I take 300 grain sandpaper, a little carb spray or oil and smooth any scratches out. I have side seals and chambers that I have been doing it to for well over a 100 sets of material now and still continue to re-use. Every now and then, I take my little springs from the side seals and stretch a hair and then put them back in.

I spray a good bit of polyurea and roofing foam and get scratches all of the time.

The experts will tell you don't, but as long as you don't take a coarse sandpaper to them you will be okay, make sure you take all of the scratches out and it will work for a long long time.
Paul Covert
Posted: Oct 17, 2010 10:46 PM
We think alike...I use a piece of glass with the fine grit paper and re-surface the side ports and mixing chamber everytime I clean my gun. I have been spraying for 6 years, and have never had this frequency of scratching/leaking.
Daniel X
Posted: Oct 19, 2010 03:22 AM
I see nothing wrong with a piece of glass and some sand paper... You have to be part mechanic and part MacGyver to spray foam anyways.

I've had scratches come out of nowhere before too, mostly on the Iso side of the chamber though.

I've broken drill bits off in the chamber and heated it up with a torch to get them out... Graco wouldn't like that either, but new chambers aren't cheap.
dave defehr
Posted: Oct 11, 2012 01:17 AM
I see alot of guys heat up the mixing chamber to remove the broken bit. How hot do you have to get it, and does it just fall right out?
Linerman
Posted: Oct 11, 2012 05:54 PM
Here's the trick, if you broke it all the way in use the bit you just broke and insert it into chamber so you can spin the bit inside the chamber to ensure it is free to move. With the chamber secure in a vise or vise grips, slowly heat the nozzle of chamber(not cherry red just enough) then you have to sorta whack the other end with a hammer that will make the broken bit slide out enough to be pulled out with some pliers.
dave defehr
Posted: Oct 11, 2012 10:52 PM
Thanks alot, I'll give it a try.
dave defehr
Posted: Oct 25, 2012 11:12 PM
Anyone have any tricks to getting the broken drill bit piece out of the side port of an AR2020 mix chamber. I have tried soaking it in solvent for about a week and blowing it out, and heating it up and tried knocking it out and still stuck. I think it might be toast. Thanks for any help.
Linerman
Posted: Oct 27, 2012 12:14 PM
I've never broke a bit in the side ports, but I would try a small wire and push from the other side. The welding tip cleaners which have multiple wire gauges would have a wire that would fit.
Caleb DeFord
Posted: Oct 27, 2012 10:00 PM
I've only had one bit break in my mixing chamber, so I'm not real experienced at getting them out, but the one time it did happen I simply pulled the trigger and the foam blew it right out.

-Foamilyman
dave defehr
Posted: Oct 28, 2012 07:48 PM
Thanks for the tips guys, unfortuneately from what I understand the side ports on the AR 2020 are uneven therefore you cannot push the broken piece from one side to another. I'll try the welding wire method but if this doesn't work I'm throwing it out.
Linerman
Posted: Oct 29, 2012 06:20 PM
That's correct the side ports are offset. But the welding tip wire cleaners have wires that should be thin enough to all the way through. Again, I've never broken a bit in the side ports so really don't have any tried and true methods that work.

You could look into sending it in to www.spfdepot.com I know they remove broken bits from the nozzle but not sure about the side ports.

Good Luck.
dave defehr
Posted: Oct 31, 2012 11:52 PM
Thanks for the info. I'll still try the wire method first then if that doesnt work I'm tossing it. Again thanks.
Anthony Scarpelli
Posted: Nov 02, 2012 12:05 PM
I've heard people using a torch to heat and expand the mixing chamber.

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