Needle Removal: From Front or Back

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Stevekir

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I asked Harder and Steenbeck for their recommendation on whether the needle should be removed and replaced from the front or the back of the AB. (Advice on various Internet sites seems evenly divided on this point.) I pointed out to them that removing from the back risked pulling paint into the trigger area and making a mess.

They said: "We recommend changing the needle from the backside because of our drill-marks on our needle's rear end. If you push it several times from the front side through the needle seal, the mentioned drill-marks may damage the seal made of PTFE."

So, its the back for me every time (for airbrushing I mean).
 

john

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I always put it out from the front and replace it the same way it came out, like you said pulling paint up can cause problems, and if you put it in from the back there is a risk of bending the needle tip on the way in, and it doesn't take much to bend them
 

stona

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I usually remove and reinsert needles from the back. This because I am lazy and can't be ars*d to remove the nozzle cap etc to withdraw the needle. I don't see that it makes any difference to the needle packing O ring. One way or another the needle has to pass through it and I've never had issues dragging paint back through it.

Cheers

Steve
 

Ian M

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I'm an in from the back out from the front type. I do though have to remove and replace from the rear on one of them. There is a knob at the back end of the needle.

I just find it easier to get the needle though the packing hole.

Ian M
 
S

Stevekir

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\ said:
I usually remove and reinsert needles from the back. This because I am lazy and can't be ars*d to remove the nozzle cap etc to withdraw the needle. I don't see that it makes any difference to the needle packing O ring. One way or another the needle has to pass through it and I've never had issues dragging paint back through it.Cheers

Steve
I assume that you remove the needle only when cleaning the AB. But if you don't remove the nozzle cap etc., how do you clean them?

I think Harder & Steenbeck's point is that it is only by removing and replacing from the back that you avoid the drill marks as they call them, (which are at the back end of the needle, at least are on mine) passing through the seal. Perhaps the drill marks, being cutouts, might tear the seal.
 
G

Gomer Pyle

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I also use a H&S brush and I have always flushed it through before removing the needle and this I do by pulling it out from the back, but I do actually re-insert it from the front, due to the risk of damage to the needle, and I haven't tron a seal yet. You can however feel a slight resistance when the back-end of the needle, where the two little protrusions are, passes the seal - not much though.

/Daniel
 
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I do the same as Steve, I have always taken the needle out of the back and put it back in the same way and haven't had any problems, I really can't see how you can damage the needle, you run more risk going out and in through the front as you'll be putting more pressure on the tip, plus, you run more chance of damaging the main seal as well as wrecking the small 'O' rings...
 
R

Roobarb

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Steve,

Although I've never used a H&S I agree with Ian,out from the front in through the back,less chance of getting a possible build up of paint or ink in the air valve.it also allows a quick dip in cellulose thinners for the nozzle.

Malcolm
 

colin m

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\ said:
Steve,Although I've never used a H&S I agree with Ian,out from the front in through the back,less chance of getting a possible build up of paint or ink in the air valve.it also allows a quick dip in cellulose thinners for the nozzle.

Malcolm
Me to,

I read this was the way to do it, so that's what I do. I've got a H & S but haven't noticed the marks on the needle - I'll have to check, then may be adopt the other method !
 
B

bluebottle

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\ said:
I asked Harder and Steenbeck for their recommendation on whether the needle should be removed and replaced from the front or the back of the AB. (Advice on various Internet sites seems evenly divided on this point.) I pointed out to them that removing from the back risked pulling paint into the trigger area and making a mess.They said: "We recommend changing the needle from the backside because of our drill-marks on our needle's rear end. If you push it several times from the front side through the needle seal, the mentioned drill-marks may damage the seal made of PTFE."

So, its the back for me every time (for airbrushing I mean).
IIRC, the "drill marks" at the rear of the needle are peculiar to the .35 size and not to the other needle sizes .

Just need to check which one is currently in my Evo...
 
B

Buttonman

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Out through the front cleaned and polished with wet and dry then lubed with super lube back in through the front, nice bit of lube on the O ring better seal and know paint mucking up the inners.

Martin
 
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As an ex re-finisher I wouldn't use w/d on the needle too often, it removes microns off the surface each time you do it!

Eventually you will have an issue with fit in the seals!

Gregg
 
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