Read Gum dust and Stihl HD Filters

[David (saltas)]

What everyone else said about K&N

They are ok for auto use at a race track that is clean but we have "bulldust" on some of our corrugated byways and a KN is also CRAP on these roads too but the big three rick mentioned are soooo much better.
K&N are crap on a saw used OZ with the notorious red gum dust.

KN was quick fix that is a couple of years old now and it was not up to the task.

The new HD2 filters like what comes standard in my MS261 are a quality unit that I cannot find any reason to criticize.
It makes me feel all smug like knowing I have the best filter money can buy as standard on my saw.
My heart glows each time I clean my saw as I know that it will be clean inside each time I remove the filter to knock the dust of it.

 

[MCW]

The new HD2 filters like what comes standard in my MS261 are a quality unit that I cannot find any reason to criticize.
It makes me feel all smug like knowing I have the best filter money can buy as standard on my saw.
My heart glows each time I clean my saw as I know that it will be clean inside each time I remove the filter to knock the dust of it.

Phew - lucky you added "as standard" or I was gonna go all Crazy Dolmar HD Fan on your ass

 

[annie wilson]

Dust can be made up of many different things. And since it comes in all sizes, the air purifier must have filters that are able to trap various size of dust.

 

[Stihlman441]

All i know is the new HD2 filters work,i have them on all my saws and a little grease around the threaded filter shaft and filter hole and all is good.Have a heap of the old filters for sale cheap.

 

[deye223]

$50 here what about up your way

 

[Stihlman441]

Cant remember champ i got a heap in one go.

 

[BobL]

Dust can be made up of many different things. And since it comes in all sizes, the air purifier must have filters that are able to trap various size of dust.

As I have spent most of my working life dealing with dust I feel I can comment on this. As you say dust comes in wide range of sizes but there is no filter that can exclude all dust. There are relatively few filters that can filter invisible dust, that's dust smaller than around 5 microns in size. Below 0.1 microns the are even fewer filters and at around 0.01 micron we are talking dust consisting only of of some thousands of atoms and the filtration becomes even more problematic. Most people don't even realise that the average visibly clean urban atmosphere contains around 1 million dust particles per cubic ft of 0.3 microns or greater. In a dry pristine forest the number of dust particles might drop to 100,000 per cubic ft of 0.3 microns or greater. Many of these are made up of wood fibres since exposed wood sheds small amounts of fibre on a continuous basis. Most CS don't realize that a lot of this fine dust goes straight through the best filters and panty hose that money can buy and we just don't even see it.

Fortunately the finer the dust the more like a gas it becomes and if it's wood it will just aspirate just like air and burn like gas. Too much of it can contribute to carbon build up inside the cylinder and around the exhaust but this can be dealt with in due course. A potential problem for small engines like CS is that when the concentration of very fine dust is high it easily gets into the carby and may aggregate to form particles big enough to block fine orifii and jets etc and cause the saw to run lean. When this does happen the blockage is usually so severe it cause the saw to stutter and the operator then sets about cleaning the carby - more dangerous is when the degree of lean-ness produced still just allows the saw to run but the degree of lean-ness is just like the H-screw was backed off too far which can burn out a saw very quickly. A couple of years back Lakeside53 posted a thread showing this effect in the Chainsaw forum. This is why even using the very best of filters it still pays to clean the carby occasionally.

 

[BobL]

Dust can be made up of many different things. And since it comes in all sizes, the air purifier must have filters that are able to trap various size of dust.

This is most interesting. There is someone called "Annie Wilson" that also just started posting general and sometimes meaningless statements on an Aussie woodworking site. I suspect Annie maybe a softbot of some kind - :msp_confused:

 

[MCW]

Hi Bob.
Great to see you around again mate
I agree on your comments regarding dust too. There is also real dust too that if enough gets through your filter will give many saws a .020" rebore real fast
Annie must have different chainsaws to me as although we do indeed have an air purifier it is 240 volts and confined to the bedroom...

 

[tdi-rick]

[snip]
... although we do indeed have an air purifier it is 240 volts and confined to the bedroom...

is that just a euphemism Matt ? :monkey:

Bob, one of your contemporaries over there also posts on here occasionally and is heavily into filtration research.

 

[MCW]

is that just a euphemism Matt ? :monkey:

A euphemism is the substitution of a mild, inoffensive, relatively uncontroversial phrase, for a frank expression that might offend or otherwise suggest something unpleasant to the audience.

Not sure, I had to look it up Good to see you round too Rick. Hows the 7900 going? Haven't spoken to Al for a bit.

 

[David (saltas)]

BobL

nice comments

I did a course with wayne dearnes (oil and toil) mech engineer tribology went to ginger beer school in Perth learnt a lot from him. He works this side of the country now and is a consultant for castrol and a few mining companies.

 

[NORMZILLA44]

Good thread feller's, and because of you guy's and threads alike I am running hd-2 filters in all my Stihl saws now. For years loggers here had a problem with redwood dust being real fine too. Even though I am overboard on my filter cleanings and don't get as many fines as you guys I am running them. Although I have noticed with all of our sudden oak death here the dust is getting finer, when we go to take them down they have usually been standing dead a year or so, and have pretty fine dust. Thanks for the good filter lesson's down under btother's:msp_thumbsup: The Aussie red gum from hell thread I think it was, was pretty good I thought that started to open my eyes.

 

[young]

hd2 one of the best period.

 

[NORMZILLA44]

I agree buddy, and I'm sold. I noticed all of our new saws we are getting come with them stock now, which is nice.

 

[MHouse1028]

i do ton's of sawmilling with my 084 and have a hd filter on it and when im milling white ash i have to clean my filter after every slab ..if i didn't it would just murder the saw..my intake gets dirty just like yours in the pictures ..so i'm there with you that stihl cant filter air..my husqvarna's dont do this at all EVER haha