Author Topic: Paint leaks from fuji hvlp air diffuser  (Read 6000 times)

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Offline usatu

  • Posts: 121
Paint leaks from fuji hvlp air diffuser
« on: February 01, 2017, 08:52 PM »
Hi-experts,

While I am still figuring out my finish problems, I keep getting paint drips from one side of air diffuser and one side of air cap also got paint on it. Through manual, I thought it is caused by needle packing nut. Apparently that's not the cause. Please advise if you know the solution.

Another issue is I probably loose the needle packing nut too much and now got a leak in the nut when I pull the trigger. I remembered that needle packing nut's gaps positioned horizontally. If you have the T series gun, can you please help me look?

Thank you so much!

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Offline Tim Raleigh

  • Posts: 3483
    • Oakville Cabinetry
Re: Paint leaks from fuji hvlp air diffuser
« Reply #1 on: February 01, 2017, 09:04 PM »
Photo's please.
Tim

Offline tjbnwi

  • Posts: 5310
  • Cedar Tucky Indiana
Re: Paint leaks from fuji hvlp air diffuser
« Reply #2 on: February 01, 2017, 09:07 PM »
Tighten the packing nut one quarter turn at a time until the leak stops. Make sure the needle moves freely.

Check the back of the air cap, there may be a little paint/finish on it. Make sure you put the air diffuser back in the gun last time you cleaned it.

Tom

Offline usatu

  • Posts: 121
Re: Paint leaks from fuji hvlp air diffuser
« Reply #3 on: February 01, 2017, 09:22 PM »
Photo's please.
Tim

I will do it tomorrow. It is the bottom part that leaks.

Offline tjbnwi

  • Posts: 5310
  • Cedar Tucky Indiana
Re: Paint leaks from fuji hvlp air diffuser
« Reply #4 on: February 01, 2017, 09:26 PM »
Sounds like you forgot the nylon seal.

Tom

Offline usatu

  • Posts: 121
Re: Paint leaks from fuji hvlp air diffuser
« Reply #5 on: February 01, 2017, 09:29 PM »
Will try tomorrow. I cleaned everything and put it back and still got leaks before I touched needle packing nut. According to manual, LEAKAGE FROM THE NOZZLE
This occurs when the Needle Packing Nut is too tight compressing
the Needle Packing #12 tightly around the Needle.
But I found is big leaks come from the diffuser holes and a tiny bead of paint on nozzle and needle tip after pulling the trigger. So I am not sure manual tells the solution on that.

Tighten the packing nut one quarter turn at a time until the leak stops. Make sure the needle moves freely.

Check the back of the air cap, there may be a little paint/finish on it. Make sure you put the air diffuser back in the gun last time you cleaned it.

Tom

Offline usatu

  • Posts: 121
Re: Paint leaks from fuji hvlp air diffuser
« Reply #6 on: February 01, 2017, 09:30 PM »
2 plastic rings? I put those on.
Sounds like you forgot the nylon seal.

Tom

Offline wptski

  • Posts: 443
Re: Paint leaks from fuji hvlp air diffuser
« Reply #7 on: February 01, 2017, 09:50 PM »
Packing nuts don't need to be removed for normal cleaning only if replacing it.

A paint leaking from the air diffuser means that your nozzle is leaking from its threads to the diffuser.
« Last Edit: February 01, 2017, 09:57 PM by wptski »
Bill
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Offline usatu

  • Posts: 121
Re: Paint leaks from fuji hvlp air diffuser
« Reply #8 on: February 01, 2017, 10:08 PM »
Packing nuts don't need to be removed for normal cleaning only if replacing it.

A paint leaking from the air diffuser means that your nozzle is leaking from its threads to the diffuser.

Does that mean tighten the nozzle more?

Offline tjbnwi

  • Posts: 5310
  • Cedar Tucky Indiana
Re: Paint leaks from fuji hvlp air diffuser
« Reply #9 on: February 01, 2017, 10:09 PM »
Loosen the nozzle and reseat it.

Paint moves from the cup, into the fluid chamber and out the nozzle into the air stream. If everything is correct no fluid ever enters the air chamber in the gun body. As Bill stated, the fluid has to be coming from the nozzle to body area.

Check the clock on the diffuser, make sure it's set on the pin properly.

Tom

Offline wptski

  • Posts: 443
Re: Paint leaks from fuji hvlp air diffuser
« Reply #10 on: February 02, 2017, 06:32 AM »
Does that mean tighten the nozzle more?
Maybe, there isn't a seal of any kind on the nozzle as it just relies a on a tiny shoulder to seat properly and seal.

Here's a video from Fuji that may help you.

 
Bill
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Offline tjbnwi

  • Posts: 5310
  • Cedar Tucky Indiana
Re: Paint leaks from fuji hvlp air diffuser
« Reply #11 on: February 02, 2017, 10:27 AM »
There is no seal nozzle to buy. It is a seat fit.

Tom

Offline wptski

  • Posts: 443
Re: Paint leaks from fuji hvlp air diffuser
« Reply #12 on: February 02, 2017, 12:24 PM »
There is no seal nozzle to buy. It is a seat fit.

Tom
Yes, it relies on its threads and a slight shoulder to butt up against.
Bill
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Offline usatu

  • Posts: 121
Re: Paint leaks from fuji hvlp air diffuser
« Reply #13 on: February 02, 2017, 05:15 PM »
Tried a different nozzle and still get the same problem. But if I remove air diffuser and put nozzle on , no water leaks. So I am not sure whether it is the plastic ring on air diffuser going bad. I also can hear air leaking sound from the cup.

There is no seal nozzle to buy. It is a seat fit.

Tom
Yes, it relies on its threads and a slight shoulder to butt up against.

Offline wptski

  • Posts: 443
Re: Paint leaks from fuji hvlp air diffuser
« Reply #14 on: February 02, 2017, 08:02 PM »
Tried a different nozzle and still get the same problem. But if I remove air diffuser and put nozzle on , no water leaks. So I am not sure whether it is the plastic ring on air diffuser going bad. I also can hear air leaking sound from the cup.
I don't have a T-70 to play along here but it seems that the air diffuser is part of your air path to the air cap not the product being sprayed "unless" it's stopping the nozzle from sitting properly and therefore leaking.  The nozzle has to be removed before the diffuser and divider as the video shows.

Maybe Tom or Tim can answer as they both have a T-70?   
Bill
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Offline Tim Raleigh

  • Posts: 3483
    • Oakville Cabinetry
Re: Paint leaks from fuji hvlp air diffuser
« Reply #15 on: February 02, 2017, 10:25 PM »
Tried a different nozzle and still get the same problem. But if I remove air diffuser and put nozzle on , no water leaks. So I am not sure whether it is the plastic ring on air diffuser going bad. I also can hear air leaking sound from the cup.

I still need pictures of your gun and cup and those areas that you think are leaking.
Tim

Offline usatu

  • Posts: 121
Re: Paint leaks from fuji hvlp air diffuser
« Reply #16 on: February 03, 2017, 08:23 AM »
Sorry,only have one with water dripping. Thanks

Offline JCLP

  • Posts: 743
Re: Paint leaks from fuji hvlp air diffuser
« Reply #17 on: February 03, 2017, 09:22 AM »
From the picture I see a couple of things.
First, replace the check valve tube. The inside looks dirty. Both tubes and valve.
Second, you need to tighten the fluid nozzle as tight as you can. This should prevent any leakage that you are getting.
Thirdly, you may want to replace the diffuser seal.
Fourthly, make sure when you tighten the metal collar as well.

Cheers,
JC


Offline wptski

  • Posts: 443
Re: Paint leaks from fuji hvlp air diffuser
« Reply #18 on: February 03, 2017, 10:01 AM »
From the picture I see a couple of things.
First, replace the check valve tube. The inside looks dirty. Both tubes and valve.
Second, you need to tighten the fluid nozzle as tight as you can. This should prevent any leakage that you are getting.
Thirdly, you may want to replace the diffuser seal.
Fourthly, make sure when you tighten the metal collar as well.

Cheers,
JC
Yeah, looks like water inside the tube or is that just on the outside?  Is the hole in the cup baffle positioned for the angle your using it?  If that's wrong plus a bad check valve, you's get the product or water in this case in your air passage ways.
Bill
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Offline Tim Raleigh

  • Posts: 3483
    • Oakville Cabinetry
Re: Paint leaks from fuji hvlp air diffuser
« Reply #19 on: February 03, 2017, 10:08 AM »
Sorry,only have one with water dripping. Thanks

Thanks.
Can you take a picture of the inside of the gun where the nozzle threads into the gun and the individual parts.
It appears the leak is coming from the fluid nozzle and it needs to be tightened, but it may be that the thread is clogged with finish and preventing a proper seal. Don't over tighten the nozzle.
It could be the check valve is leaking, but usually that creates intermitment problems not a consistent stream.
Tim

Offline usatu

  • Posts: 121
Re: Paint leaks from fuji hvlp air diffuser
« Reply #20 on: February 03, 2017, 05:38 PM »
I will do pictures tomorrow. The gun is not with me. I cleaned the tread really well after the leaks happened. If the treading is not sealing well,it should leak after I put the nozzle on without air diffuser,right? I am getting a rebuild kit to replace the parts.

Offline usatu

  • Posts: 121
Re: Paint leaks from fuji hvlp air diffuser
« Reply #21 on: February 07, 2017, 09:57 PM »
I got the rebuilt kit yesterday and after changing two plastic rings , it stopped leaking. But it started again today. Also the  cup bubbles too. Pls see pictures.

The flex tube leaks too as the front has a small cut. Tried to wrap in gas line seal tape. Wondering whether I can cut off that part and attach t the rest back  to connector?

Thanks

Offline wptski

  • Posts: 443
Re: Paint leaks from fuji hvlp air diffuser
« Reply #22 on: February 07, 2017, 10:22 PM »
If the tube is cracked just cut off the area, no problem as long as it reaches it's fine.

You might try one wrap of some Teflon tape on the nozzle threads.
Bill
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Offline brewster201

  • Posts: 61
Re: Paint leaks from fuji hvlp air diffuser
« Reply #23 on: February 08, 2017, 07:32 AM »
Hello it appears to me that you have the fluid adjust open way too much and it is not atomizing properly. The excess is running down the tip. Try reducing to about 3 turns open and try again. What is the size of the nozzle/needle set?
Also replace the check valve on the hose, if it is plugged you will not pressure up the paint cup, cut out the bad section of hose and or replace

Bruce
« Last Edit: February 08, 2017, 07:38 AM by brewster201 »
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Offline wptski

  • Posts: 443
Re: Paint leaks from fuji hvlp air diffuser
« Reply #24 on: February 08, 2017, 07:57 AM »
Hello it appears to me that you have the fluid adjust open way too much and it is not atomizing properly. The excess is running down the tip. Try reducing to about 3 turns open and try again. What is the size of the nozzle/needle set?
Also replace the check valve on the hose, if it is plugged you will not pressure up the paint cup, cut out the bad section of hose and or replace

Bruce
Is a T-70 drastically different than a Gxpc where full open is 2 1/2 turns?  Close the flow all the way, pull gently on the trigger, mark the flow control knob, open the flow control allowing the trigger to move back the it hit the gun body and count the turns.  I've read read comments mentioning 5-6 turns on a T-70 so I'm not sure if that is possible.
Bill
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Offline usatu

  • Posts: 121
Re: Paint leaks from fuji hvlp air diffuser
« Reply #25 on: February 08, 2017, 05:48 PM »
If the tube is cracked just cut off the area, no problem as long as it reaches it's fine.

You might try one wrap of some Teflon tape on the nozzle threads.

So far works great with that trick!Thanks

Offline usatu

  • Posts: 121
Re: Paint leaks from fuji hvlp air diffuser
« Reply #26 on: February 08, 2017, 05:50 PM »
Hello it appears to me that you have the fluid adjust open way too much and it is not atomizing properly. The excess is running down the tip. Try reducing to about 3 turns open and try again. What is the size of the nozzle/needle set?
Also replace the check valve on the hose, if it is plugged you will not pressure up the paint cup, cut out the bad section of hose and or replace

Bruce

Looks like the tread inside gun has problems.

Offline tjbnwi

  • Posts: 5310
  • Cedar Tucky Indiana
Re: Paint leaks from fuji hvlp air diffuser
« Reply #27 on: February 08, 2017, 06:10 PM »
Contact Fuji, they should be self sealing.

Tom

Offline Tim Raleigh

  • Posts: 3483
    • Oakville Cabinetry
Re: Paint leaks from fuji hvlp air diffuser
« Reply #28 on: February 09, 2017, 10:33 AM »
I got the rebuilt kit yesterday and after changing two plastic rings , it stopped leaking. But it started again today. Also the  cup bubbles too. Pls see pictures.

There is definitely something wrong there.
You should not be getting any amount of paint in that area.
You really need to find someone in your area that can take a look at that gun and either fix it or throw it away.
No wonder you are having problems getting a good coat.
Did you buy that gun second hand or new?
Tim

Offline usatu

  • Posts: 121
Re: Paint leaks from fuji hvlp air diffuser
« Reply #29 on: February 09, 2017, 07:37 PM »
I bought it new.