Iwata seals survey, what aircap seals have you ?

[Merlin]

Hi,

What seals have your Iwatas around the screw thread on the back of the aircap, aircap being the first item you screw on over the brass nozzle ?

Are seals there needed, one would think the answer is of course they are else why are they there !

I have an Iwata HP-SB and it had a PAINTED ON reddish orange seal around that screwthread, just a thin band up under the backplate of that aircap. Thus when screwing the aircap into place it caused a seal at the last few turns.

It dissolved away the first time I cleaned the aircap out in cellulose.

Is it needed ? Since then I get pulsating paintflow, cant spray a constant thickness line. It is said its not required but lack of sealant there on any model of airbrush will pulsate lines ! If not required why was it there !!!

Maybe its not that. The HP-SB has push fit (no seals) side cups with choice of left or right of airbrush, a metal stopper is used on the opposite side.

Is this ok ? Any minutest gap there will see air in, two push fits, double the chance of leakage. Would that explain the pulsation ? H&S has a screw thread with seal for their side cup.

I can't place an O ring over that screwthread as it then places the aircap more fwd of the nozzle so ruining the designed vacum creation point.

I am also not happy that the needle sits hugging the nozzle side through its fore/aft motion. Correctly built airbrushes have all items on a centreline not offset !

Anyone care to look at their Iwata, is the needle dead centre of the nozzle ? A donut ring hole not a crescent shape hole is surely correct for paint flow and non clogging. This Iwata can't spray acrylics however much I try brands and flow agents etc.

Merlin

[denstore]

Use wax as a sealer on the threads and on the side cup mount.

Edited August 22, 2014 by denstore

[little-cars]

I generally use tacky wax if I suspect a seal is suspect.

Not sure about the pulsing air/paint.

It sounds like the brush is new, so I would either contact the dealer you bought it from.

Or the importer ( www.airbrushes.com in the UK).

Paul

[Merlin]

Denstore,

When you say wax, I am aware of wax candles but how does one make sure a 360degree airtight seal is obtained with such wax and what wax and how to apply it ?

I just am puzzled that a company like Iwata expect us to try and make a seal.

Paul, What is tacky wax and for someone who keeps their airbrush scrupulously clean, might this gradually invade areas I dont want it to ?

Mess up the screw threads etc ?

Are all Iwatas blessed with dissolving seals here and need for diy ?

I have trepidation on placing wax into a hole that is for cup fit as it may in due course eventually get into the interior and paint feed with consequences on my paint finish.

With no selas ever there in the cup push, I havent a clue if the cup fit is 10% perfect or not.

What would the symptoms of imperfect cup fit and bung fit be there ?

Badger 200 has a push fit for its jar and cups as well.

Merlin

Edited August 22, 2014 by Merlin

[Ratch]

Wouldn't PTFE tape work?

[Rick Brown]

Bees wax is used on the Iwatas.

I use it sparingly around the air cap, needle cap and nozzle threads.

All recommended by Iwata.

There is a O ring, but that's in the air valve and shouldn't get anywhere near paint or solvents in normal usage.

This O ring just needs cleaning once in a while (or if the trigger gets lazy) then lubing with a tiny smidgen of high quality machine oil.

I use some for a sawing machine.

My bees wax came from Hobit craft. I think it was about £3 for enough to last at least 10 generations!

HTH,

Rick.

[denstore]

Denstore,

When you say wax, I am aware of wax candles but how does one make sure a 360degree airtight seal is obtained with such wax and what wax and how to apply it ?

I just am puzzled that a company like Iwata expect us to try and make a seal.

Paul, What is tacky wax and for someone who keeps their airbrush scrupulously clean, might this gradually invade areas I dont want it to ?

Mess up the screw threads etc ?

Are all Iwatas blessed with dissolving seals here and need for diy ?

First, i have never had any Iwata that needed wax or any other added sealant in order to work. They have just kept working for years of use.

But I usually wax every part now and then, not to seal anything up, but because it makes the brush a lot easier to clean, and wax also function as a lubricant. I use silicon free hard cake car wax.

[little-cars]

Denstore,

When you say wax, I am aware of wax candles but how does one make sure a 360degree airtight seal is obtained with such wax and what wax and how to apply it ?

I just am puzzled that a company like Iwata expect us to try and make a seal.

Paul, What is tacky wax and for someone who keeps their airbrush scrupulously clean, might this gradually invade areas I dont want it to ?

Mess up the screw threads etc ?

Are all Iwatas blessed with dissolving seals here and need for diy ?

I have trepidation on placing wax into a hole that is for cup fit as it may in due course eventually get into the interior and paint feed with consequences on my paint finish.

With no selas ever there in the cup push, I havent a clue if the cup fit is 10% perfect or not.

What would the symptoms of imperfect cup fit and bung fit be there ?

Badger 200 has a push fit for its jar and cups as well.

Merlin

I'm not sure what the red you saw was, it could just be residue from them testing the brush, but it doesn't sound like a seal/O ring to me, that's why I suggested you contact the retailer who sold it to you and/or the importer.

Tacky wax is a small tub of wax that is slightly soft at room temperature. Often used by modellers to holding small parts.

Can be useful for filling tiny gaps for fault isolation, for example if you think there is is wear on a screw thread, on the air cap or nozzle.

I've never had a problem with the Iwata push fit cups, just push them in & twist a little, never used anything to hold or seal them in.

Paul