November 3, 2014 at 1:21 am #47854
Im getting dry spray every time i use my gravity fed spray gun. The gun will spit and make a whistling noise during operation. Its the same noise you get when you run out of paint. It makes that sound all the time, with tiny gaps in between. Ive tried the following:
Different ratios of primer-thinner
Different air pressures
Thoroughly cleaned the gun. Found some clogged up paint in the air cap.
The gun itself is painted black, part of that paint was peeling off inside the fan control section, so i removed it as i thought it may be flapping around causing fluctuations in air flow?
Cleaned around the packing nut that the fluid needle slides through.
Some gummed up primer came off it the other day.
I have another gun also. Its packing nut is plastic. The packing nut on this gun is fabric it doesnt look smooth. It looks like the fabric may have ripped a little whilst cleaning etc.
The needle sits tight in it though.
Wondering if this could be a cause?
The air temperature is a bit low at the moment. Ive been spraying in 10-15 degrees centigrade.
Maybe i could warm my garage with my flood lamp lead light and a oil heater for a while before spraying?
Also maybe my paint itself is too cold and i should keep it in the house?
I havent adjusted the fluid control a great deal and read somewhere this could be a cause.
Im spraying filler primer at a ratio of 1 part thinner to 1.5 parts paint.
Im running a 3bhp, 14cfm oil based compressor. I have a water trap/filter/regulator unit in place. This is after a coiled plastic hose connected to the compressor.
The gun used to spray paint more smoothly when i first got it. Its got a 1.5mm fluid tip so kind of an all rounder.
Im using a hand span fan and keeping the gun a hand span or more away from the panel.
Ive tried moving the gun at different speeds. The paint goes on really wet the slower i move it.
I still can try some things differently in order to cure this dry spray.
Anything else i could try?
Any help will be greatly appreciated.
Thanks.November 3, 2014 at 6:20 am #47855
Sputtering, and a whistle noise? I’d bet the hole in the lid of the fluid cup is clogged. If you spray with the lid off (carefully) does it spray normally? This is common, especially when the guns aren’t cleaned particularly well.
Those old fabric packing seals work just fine. Is there any sign that fluid has leaked back out of it? Does the needle move through it with just a minimal amount of resistance?November 3, 2014 at 1:42 pm #47856
The paint pot on the gun is clean. The hole in the lid is clear. Ill clean any old paint off the gun body around the packing seal and check for leaks. It requires quite a lot of force to push the needle through the packing seal. I wouldnt say its a huge amount of force required, but it doesnt slide through easily. Thanks.November 3, 2014 at 7:12 pm #47861
[quote=”ED1982″ post=36336]The paint pot on the gun is clean. The hole in the lid is clear. Ill clean any old paint off the gun body around the packing seal and check for leaks. It requires quite a lot of force to push the needle through the packing seal. I wouldnt say its a huge amount of force required, but it doesnt slide through easily. Thanks.[/quote]
What kind of gun is this? ( Manufactured by? )November 3, 2014 at 7:19 pm #47862
Im trying to upload some photos via a iphone and iphoto. Every time i try and do this, the computer freezes. Ive attached photos and then tried it again, inserting the photos. Any ideas? Ive taken a lot of photos and videos of the situation today.November 3, 2014 at 7:22 pm #47863
[quote=”ED1982″ post=36342]Im trying to upload some photos via a iphone and iphoto. Every time i try and do this, the computer freezes. Ive attached photos and then tried it again, inserting the photos. Any ideas? Ive taken a lot of photos and videos of the situation today.[/quote]
I’ve had success with Photobucket. Is this a no-name gun?November 3, 2014 at 7:22 pm #47867November 3, 2014 at 7:25 pm #47868
That was wierd. I tried it again, it froze, then i clicked on one of the insert file boxes and they went through. It may have been because i was trying to upload a mov (movie) file before and its not allowed. Ill have to have a play and try to get the videos to come through as they are crucial. They show the fault with the gun as its operating.November 3, 2014 at 7:29 pm #47877November 3, 2014 at 7:30 pm #47881November 3, 2014 at 7:49 pm #47882
The movie files i am trying to upload are in mov format and it is not shown on the list of items you can upload. Has anyone successfully uploaded movies before? If so, what format. The gun is a common model. Its sold by lots of companies on Ebay. I found one company that has a data sheet for it. It appears to be the same type of gun. Here is a link. http://www.silverlinetools.com/en-GB/Products/Air%20Tools/Spray%20Guns/783124November 3, 2014 at 8:31 pm #47883
Ok. So that link isnt working. The gun is very much like the silverline 1.5mm 500cc model. Silverline’s website may be a uk website?. The paint level in the gun has now dropped and the sound has got more intense. Im starting off with the gun sideways and when i open the paint pot lid there is no paint going into the gun. when i last sprayed, i started off with the gun sideways then held it with the tip facing downwards as i travelled along the panel. When sideways it didnt make any strange noises. Once vertical it started whistling. Its almost like there was an air lock in the fluid chamber. earlier when i had more paint in the gun, im not sure if i stored the gun upright all the time when not in use. Would that cause a problem with the paint, or if held upright for a while should any air locks clear?
Also, i thought the paint pot was leaking at the base but its not. I put the gun down on the floor sideways and paint leaked out of the top, down the side of the pot and accumulated around the base giving the impression of a leak from there. I will upload all videos to my facebook account as im not sure how im going to put them on here. My facebook name is Edwardyemm. Ill make sure all videos are public and can be viewed by all. Here are some more photos.November 3, 2014 at 8:39 pm #47884
Now iphoto wont show me the latest photos i imported to it. Ill put the photos on facebook too.November 3, 2014 at 8:52 pm #47885
No offense man..but that gun looks like a real turd. I’d save my empties and get a decent gun with higher manufacturing tolerances….and serviceable.November 3, 2014 at 9:14 pm #47886
Agreed. This gun is a budget model. My other gun is a better quality. Its a Clarke HVLP gun. Model no AP16GF. I tried to spray filler primer through it. It has a 1.4mm fluid tip, so was expecting it to spray as well as my cheap gun used to. I gave up trying to get good results. The paint was failing to atomise correctly and landing on the panel in blobs, despite making adjustments to air pressure, fluid control etc. The cheap gun sprays the paint a little smoother.
Maybe i should be spraying the filler primer with a 1.8mm or 2.0mm gun instead? Its mixed at a ratio of 1.5 parts paint to 1 part thinner so quite thick i guess. Suppose i could also try using the primer at the normal ratio of 1-1 and see what the gun behaves like? I uploaded a video to facebook and will upload some more. My username is edwardyemm. All content is public so anyone can view it. Im considering trying a new packing seal on the cheap gun incase it may have been damaged by cleaning. I pushed a gun cleaning brush down the hole in the past and the metal end that pokes out of it may have damaged the seal?
Wondering if, even though the packing seal isnt leaking paint, it could still be drawing air if worn slightly?
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