You should soak and wash them by hand In warm water if possible. But if you want to machine wash them use warm water and gentle cycle.

Doesn't washing take out the sizing from the factory thus reducing its ability to filter properly, allowing more picked up debris to re-circulate into the air?

I've always just vacuumed a dump bag & sprayed it with Fabreeze to preserve the factory sizing.

Doesn't washing them take out the factory sizing thus reducing its ability to keep from recirculating dust back into the air?

I've always vacuumed them out & then sprayed them with Febreeze to freshen them thus preserving the original sizing.

I have found that the answer to the questions of to wash or not to wash and how to go about it is different for just about every bag.

If a bag is in excellent condition, it is not stained, reeking of mildew or dander from the original Lassie, then, BY ALL MEANS keep it away from the laundry room.

After you have emptied it in the usual manner, disassemble the bag as carefully and completely as you can.
Take it OUTSIDE and wear a dust mask if you are particularly sensitive to such things. Turn the bag inside-out and shake/scrape/beat/brush/vacuum it until MOST of the dirt is gone.
I would then take the bag back inside to a well lit work area and complete clean all of the hidden pleats and seams with a vacuum and a small brush.
Then temporarily turn the bag right side out to carefully vacuum it clean as well. Again turn the bag inside-out and evenly and completely dampen BUT DO NOT SOAK it with a DISINFECTING and deodorizing product like LYSOL spray.
Allow it to completely air dry.
Turn it right side out again.
Inspect for holes and weak seams. Repair any by darning with matching thread AND/OR applying matching iron-on, cut-to-size fabric pieces on the reverse side.
Keep irons AWAY from screen printing! Protect it with a pressing cloth or iron that area GENTLY from the reverse side.

I have found that on Hoover & Kirby bags that one of the first things to cause trouble are the metal bag bands (Hoover) and the metal mounting springs (Kirby). They RUST, stain the fabric with same and if they don't completely fall apart, the abrasive rust particles they shed steadily grind away at the integrity of the surrounding fabric.

Rarely have I been able to successfully "slide" a rusted Hoover bag band out of its fabric sleeve without shredding the fabric and Kirby springs are completely enclosed. The remedy requires just a little bit more skill and practice than darning holes. A seam ripper or a pair of small manacure-like sewing siscors is needed to patiently and carefully open up the sleeve holding the band or the spring. Do this with an old towel in your lap to catch the shower of dirt and rust that will fall out of the sleeve.
Brush and/or vacuum the opened sleeve area as clean as possible. I have had little luck removing rust stains from these fabrics. I have even tried things like Lime-Away acidic cleaners. There MAY have been some improvement but maybe I was just trying to convince myself it was worth the effort and the acid could not have done the fabric any favors. The consolation is that more often than not these stains are almost completely hidden when the bag is reassembled and installed.
Hoover bag bands can be wire brushed and/or sanded smooth and reused, or, if necessary replaced with a NOS band or at least one in better condition. I've never tried, but I wonder if one of those self-tightening plastic cinch straps would be a good substitute?
Why Kirby used metal springs on their bags mouths remains a mystery to me. Nine times out of ten I find them crumbling with rust and broken into six pieces. I replace them with a standard-issue Eureka/Sanitaire conventional upright round rubber belt.
For Hoover bags, resew the sleeve either with the band in position or leaving enough room to slide it in later. Follow the original stitching holes as a guide. The first option requires three hands, the second, the patience of Job. You pick.
The belt or spring for Kirby bags must be sewn into the sleeve. Again, follow the old stitching.

If a bag is truly a diamond in the rough, is filthy dirty but is in otherwise good condition or shows promise of being repaired, by all means wash it! It is my understanding that most "modern" shake-out bags (read post 1925!!) depend on the tight weave of the fabric rather then chemical sizing for their filtering properties. Besides, if the choice is a beautiful, fresh bag or some nasty thing you don't even want to bring into the house, the choice is easy. The only bag that I have washed and then from which noticed across-the-room-visible dust leakage was from a Kirby Classic ?, constructed out of a denim-like material with vinyl pin stripes. . .decidedly cheaper and less effective than its predecessors.

I wash by hand or in a front loading machine on "hand wash" cycle with the bag turned inside-out, THOROUGHLY vacuumed and brushed and ALL hardware removed. If you have a top loading machine, use the most gentle cycle and only allow the machine to agitate very briefly two or three times over a half-hour soak.
Dark colors WILL bleed like CRAZY. So wash each bag separately.
Screen printing on Hoover bags WILL fade no matter how you wash them and, TRAGICALLY, can wash away almost completely if put in a machine.
I have had much better luck with Kirby screen printing.
Rinse repeatedly and gently until the water is as clear as it will be.
Add fabric softener to the last rinse.
Do NOT tumble dry. Do not wring if you hand washed the bag. Drip and hang dry, iron, protecting the screen printing, and proceed with reassembly and repair.

IN THEORY dry cleaning may be the best solution of all. Screen printing that dissolves in water just might come out completely unscathed from a bath in dry cleaning fluid. Similarly bleeding and fading may be less of an issue. I've just never tried it . . . .Hmmmmm.

I do go on!

Marty Kaplan

That's what I get for trying to be fancy.

The Kirby bag I talk about in the above post is from a Classic OMEGA, not a Classic. I was trying to use a real Greek "omega" symbol (option-z). It showed up correctly in the proof, but as a "?" in the final posting.

Marty Kaplan

That is totally awsome, you should print this in the newsletter. You have done a great job on how to clean and care of a bag.

I to do mostly the same. When I have machine washed my bags I have them to dry either outside, inside out, or just near air from window or hearter vent in the winter time. I will ad a small amount of liquid fabric softner, for fragrence which can really help. But I only wash them if they are really, really stinky and dirty. I also take it outside and brush it good and clean all of it off before I wash it.

Dry Cleaning? I have done this but, the cleaners I took it to, which was the same place my family always took our cleaning, the lady would not be happy with me briging that in because it would clog her filters, becuase of the dirt left in the bag, even though I would think I had it brushed out. Using a air compresor would help if it was outside.

To those who say "doesnt it ruin the bag?" Funny thing, as soon duest starts to fill the bad the pours in the bag start to refill again, the bag quickly comes back to normal.

Logos? Well on the older Kirbys I have gone to get some fabric paint of the same colors of course. I have repainted to logos back on by hand..

David Watters

Thanks, David.

What an interesting idea to use fabric paint to refresh screen printing. You must have a VERY steady hand and some very fine tipped paint brushes.

Once I was so compulsive as to hand embroider the "H O O V E R" on the rayon outer bag of my model 61, using the faded printing as a guide. It looks pretty swell, if I say so myself, but not EXACTLY the world's most efficient use of time and required a steady hand as well.

I had a Kirby classic omega one time that had the bag on it that was tan with little rubber dots all over it.. one day while i was using it, the pressure from the air inside caused the teeth on the zipper(which were apparently rotted and i didn't know it) to burst off, blowing the sanipocket inside out.. scared the ---- out of me.. so naturally.. not wanting to forfeit an original bag, my mother kindly agreed to sew a new zipper on..(I admit.. I know NOTHING about sewing) she said she would NEVER do that again.. she said the fabric was so tough that her fingers were sore from pushing the needle through.. and.. oddley enough.. she sewed the zipper on upside down :( BUT I didn't complain.. I was thankful that she was sweet enough to do that for me.. and I still had my original bag.. Sadly though... the bag eventually was destroyed. I had given my grandmother the Kirby cuz her Hoover concept one that she had since brand new had finally given up on her. She had a Kirby Dual Sanitronic 80 before the hoover and wanted another kirby. At this time I had a large collection of Kirby's so she and grandpa came over to pick one out. She originally chose the Tradition but decided she didn't like the paper bag system in it(made it too heavy and restricted suction) so she came back for the Classic Omega. One day last year she vacuumed up some hot ashes around the fireplace in it and completely torched the bag :( I got her another Kirby stock bag to put on it, but it's a plain gold colored bag without the original Classic patch on it.. means nothing to her, but for me as a collector it drives me crazy cuz I know I will have the vacuum again someday.