Harder & Steenbeck Evolution

[Guest]

Can anyone suggest why after using my AB I find paint has migrated up along the needle as far as the Chuck. I thought there should be a seal but can't see where one should be. The exploded diagram in the booklet dosnt show one either.
This I have only recently noticed as I clean in my usual way after use, but when I come to use it the next time the trigger is stiff and the needle dosnt move freely. Once stripped down I find a good coating of dried paint on the needle.
It may be worth mentioning that it sprays fine!!
I'm sure it hasn't always been like it.
Cheers Alan

[col68]

Hi Alan I have the same A.B and I have never had it happen to me.
What paint are you using?

[Guest]

Hi Alan I have the same A.B and I have never had it happen to me.
What paint are you using?

Tamiya acrylic.

[BarryW]

Alan, when you remove the needle do you pull it out from the back or push it out through the front? Pulling it out drags paint back into the a/b, you should push it out.

[Guest]

Alan, when you remove the needle do you pull it out from the back or push it out through the front? Pulling it out drags paint back into the a/b, you should push it out.

Barry I push it towards the front. Even after a good clean there is a generous amount of paint on the needle which suggests that paint is travelling back towards the needle chuck. Then once dry it dosnt operate smoothly until I have cleaned the dry paint off the needle.

[Guest]

Ages ago, I recall someone saying that some H&S brushes were lacking the rear seal & that a replacement kit was available. I can't remember if your AB was the one though Alan.

Drawing the needle from the front is what I do, but I'm very careful when using the 0.4 needle because it has a notch right at the end which could damage the back seal. Also when drawing it that way, it's hard to determine if the paint on the needle has come from the paint migrating up it, or from the residue forward of the trigger.

A way to check is to clean & assemble the AB, pull the trigger back fully & using tweezers, put a tiny bit of bog standard masking tape on the needle shaft just before the trigger.
The scrap of tape will become discoloured if paint is going up past the back seal.

HTH

[Guest]

Ages ago, I recall someone saying that some H&S brushes were lacking the rear seal & that a replacement kit was available. I can't remember if your AB was the one though Alan.

Drawing the needle from the front is what I do, but I'm very careful when using the 0.4 needle because it has a notch right at the end which could damage the back seal. Also when drawing it that way, it's hard to determine if the paint on the needle has come from the paint migrating up it, or from the residue forward of the trigger.

A way to check is to clean & assemble the AB, pull the trigger back fully & using tweezers, put a tiny bit of bog standard masking tape on the needle shaft just before the trigger.
The scrap of tape will become discoloured if paint is going up past the back seal.

HTH

Thank youI will certainly try this. However, I cant see a back seal in the exploded diagram in the booklet.

[Guest]

Thank youI will certainly try this. However, I cant see a back seal in the exploded diagram in the booklet.

Most don't show it Alan, I think because it's an integral part of the airbrush. I can't recall ever seeing it noted on any diagram of an AB that I've owned. But it should be there, and of if you can show that paint is migrating up the needle, you might be able to get a refund or exchange.

[stona]

There must be some kind of seal to prevent this happening. I'm not familiar with the H+S brushes, but other types have some kind of system in place to prevent paint passing to the rear of the brush through the back of the paint cup!
Iwata call it a 'needle packing set' on their brushes.
Cheers
Steve

[Guest]

Im sure the back is a set of 2 or three seals. You remove them with the long tool that has a flat face like a screwdriver but with a long pin on the end of it the diameter is the same as the inner diameter of the seals. Im sure its a set of white teflon or similar seals.

I never considered the notches in the end damaging the seals but ive had mine in since new and i dont treat my brush with much respect and they still seem good, i bought spares a while back so i dont need to be without the ab when they fail. I do get the paint working its way right back up inside but i think the seals sit quite far back.

I also throw any chemicals i want into that brush no worries. None of this namby pamby not putting cellulose in to it etc... works perfect after 2 years same seals.