Tear-down of a "decent" solder fume extractor (HAKKO, METCAL, etc.) ?  - Page 1
Forum section: electronics / general

author: onesixright
author_rank: Frequent Contributor
timestamp: October 23, 2017, 09:44:56 am
content: Hey All,I'm looking for a fume extractor, indoor. I have no option to vent it outside. I also read the different topic's about DIY versions.I saw the "industry" versions are pretty expensiveI'm curious what makes these sospecialthat its worth a whopping 500+ USD? Anybody did a review / tear-down of a Hakkok FA430 or a Metcal BVX? Looks to me like a big box with a fan and a filter. What am I missing?Thanks!

author: TopLoser
author_rank: Unknown
timestamp: October 23, 2017, 09:52:36 am
content: I took a BVX apart recently.It was just a big box with a big filter plus a very quiet 2 wire 24v brushless DC motor. Detected when the filter was blocked by measuring temperature drop of a heated thermistor - when the drive circuit for the motor failed the thermistor got VERY hot! It was a nice quality unit plus it came with a couple of flexible tubes and some clamps.If you need one then the price is fair for what is probably a fairly low volume product. The filters alone are pretty expensive.

author: Rerouter
author_rank: Super Contributor
timestamp: October 23, 2017, 10:10:39 am
content: Generally its a fan that has a fairly even flowrate over a wide range of loads (e.g. amount of muck in the filters), enough layers of filtration to prevent any one layer from clogging easily,As for price and construction, I went with building my own, polycarbonate can handle being close to a soldering iron tip without softening too bad, so i had a pick up nozzle printed to suck up 2cm behind the tip at 3 points, it catches from what i can tell all the smoke, runs it down some polyurethane hose i have spiraled around the soldering iron lead, and in to a filter box driven by a 120mm variable speed fan,This doesn't help much for my hot air gun, but i am working on that, due to how close its picking up the flux fumes, it doesnt need much airflow, going through a carbon filter, a lighlty moist spounge catcher, and a high thread count cotton sheet,For hot air rework you need something closer to a wide nozzle high airflow sucking filter like the commercial ones, simply because the amount of flux you generally end up burning off per second is far higher.

author: ElektroQuark
author_rank: Unknown
timestamp: October 23, 2017, 10:29:46 am
content: Quote from: TopLoser on October 23, 2017, 09:52:36 amI bought one with a dead motor. METCAL service sells the bare motors for about 180€. Up and running now.

author: Fraser
author_rank: Super Contributor
timestamp: October 23, 2017, 11:11:12 am
content: I have a Purex unit that sucks the smoke from the soldering tip via a stainless steel tube mounted on the handpiece. It was used with Pace seldering irons.The unit is a large cylinder with a very large area 360 degree filter surrounding a low noise AC motor and turbine. The clever bit appears to be the filter. It's construction dictates the effectiveness of the system. Turbine blowers are quite a common item but I suspect the filters are custom designed for the application, hence their high cost.My new 3D printer contains a HEPA filter to remove airborne nasty elements from the printing process before they leave the printer. I suspect the Purex soldering fumes filter unit is just a large HEPA filter. Such filters are common on vacuum cleaners but normally of smaller size and the airflow force applied to them is higher.I understand that activated carbon filters are used in cooker hoods that do not vent to outside. Replacement filter material for these is common and cheap.Fraser

author: onesixright
author_rank: Frequent Contributor
timestamp: October 23, 2017, 11:26:56 am
content: Well I love all the DIY solutions!However, I don't like to "gamble" with my health. And the problem I see is: its hard to test wetter the DIY solution is adequate. Or I'm I wrong? The problem, as I understand is, is mainly the rosin fumes (which are pretty toxic). Isgassomething a HEPA filter catches?Quote from: Fraser on October 23, 2017, 11:11:12 amSo basically its a tip fume extractor? Looks like a nice little machine!, pity, its discontinued. But probably would also cost a arm and a leg

author: Fraser
author_rank: Super Contributor
timestamp: October 23, 2017, 02:07:53 pm
content: I regret, I am no expert on air filtration. I think flux is emitted as a particulate though, as in smoke. Minuscule particulates are caught in multi layer filter membranes for of the correct permeability specification. Activated carbon is also used to remove odours but I do not know whether such are needed to process solder flux fumes.I was driven the Purex along with its hoses and stainless steel 'pick-up' tube that attaches to the soldering iron. It is a direct 'collection at source' system rather than the large 'vacuum cleaner' area collection system. If I am honest, I prefer the area collection designs as they also collect fumes from the bench area coming from any chemicals I am using, such as IPA, Methylated spirits or Acetone. I do not like having the collection tube on the soldering iron handpiece either. I now use thin Pace pencil irons so such an attachment would add to the bulk and increase cable/hose resistance to movement.Sadly all the professional grade bench filtration systems I have seen are either very bulky or very expensive. I looked at the OKI (Metcal) system as it is quite versatile in terms of its deployment. It appeared to have a much smaller filter than floor mounted units though so I am unsure how often the expensive filters need changing. Many filters specify 300 hours or 3 months of use as the time to change them. I presume this is also to avoid nasty bugs and viruses being able to populate the air filter as it draws in anything that is air borne and traps it in the filter membranes.Fraser