Fluxing With Sawdust

[PPGB]

I have read several posts and a couple of books that recommend fluxing with sawdust. Most mention using pine sawdust that they collect in their woodworking shop. Unfortunately, I don't have a woodshop, yet. However, there are several Amish sawmills nearby that mostly cut oak lumber for making pallets and have huge piles of sawdust. There are also a couple of small private sawmills in my area that cut red cedar for lumber. Does the type of sawdust make a difference? Are there some that are better than others? Are there any type that should be avoided?

I am thinking (although I may be wrong, it has happened, just ask the Mrs.), that pine is often mentioned as a good flux because of the oils and resins in the wood. If that is the case would red cedar be a good choice given the levels of oils and resins in it? Unfortunately, I don't know of any sawmills that cut pine in my area.

[jmort]

This would last you a long time
http://www.walmart.com/ip/10418554?wmlspartner=wlpa&adid=22222222227000000000&wl0=&wl1=g&wl2=&wl3=21486607510&wl4=&wl5=pla&veh=sem

[220swiftfn]

Well, the resins are the reason that pine is the best, and if that's what you want, go to Wally-world (or pet store) and pick up a bag of IIRC hamster bedding, it's shaved pine. Oak and Cedar should be fine, but there's one type of wood that puts off noxious fumes, unfortunately I can't remember which one it is!!!!! (And then there's the caveat of not using anything pressure treated or laminates/chipboard, the burning glue is bad for you......)



Dan

[waksupi]

Try them out. Some cedars I am REAL allergic to. It will depend on what you can be around.

[Wal']

If I don't have any pine sawdust on hand, I just grab a tray & my power saw & attack a log from the woodpile.

This is an Australian snowgum hardwood [alpine] & it works just as well as any pine I've used.

[5.7 MAN]

How about wood pellets used in pellet stoves? I can buy a 40# bag for about $5, which would give a large supply of sawdust. Thats what they turn into when they get broken up.

Dan

[Ohio Rusty]

If you need some pine sawdust, send me a PM with your email and I'll send you a whole box of the stuff !! I have a log home mill near me and they have huge piles of fresh pine sawdust and pine shavings. Alot of the horse people come there to get huge bags fulls for bedding. I happen to have two large trash bags full at the house as we speak ...er ...type. I'm gonna mulch around the plants. I like to let mine set open in the garage to let the moisture out and help it dry. Moisture and hot lead don't play nice together !!
I never buy anything if I can scavenge it or get it for free ....... Either I'm frugal or a cheapskate ......take your pick !!
Ohio Rusty ><>

[cbrick]

I would avoid the cedar if possible as many people are very sensitive to the smoke. No doubt it would flux as well and if you have good ventilation & avoid the smoke & that's what you can get . . .

It's not the sawdust that does the fluxing but rather the very porous carbon the sawdust turns into.

Rick

[btroj]

I just use wood shavings intended for small animal bedding. Cheap, easy to find, and a bag will last a loooonnnnnnggggggg time.

The burning is important as it produces the CO that does the reducing. The charcoal then grabs impurities by trapping them in the numerous microscopic pores in the charred wood.

[I'll Make Mine]

I'll add another to avoiding the cedar; the same stuff in cedar that makes it repugnant to clothing-eating insect larvae (terpenes?) makes it undesirable for humans to breathe in the concentrated form of smoke. Also as noted, many folks are allergic to cedar and even handling the sawdust/shavings can be a problem. Generally, it's the rosin in pine that's having the most effect compared to charcoal (for reduction or oxides) or waxes and oils (also reducers) -- pine shavings or dust reduces oxides as well as anything else, but the rosin also promotes mixing of the metals in the alloy (same reason rosin is used as flux for soldering electronics). The rosin baseball pitchers use to enhance their grip on the ball, or that weight lifters use to get a better hold on the bar, is the same stuff (also rosin for any kind of stringed instrument bow will work, though it's more expensive; we don't care about the distinctions between violin, viola, cello, and bass viol); adding that to the oak cuttings would give a similar effect to using pine sawdust.

Possibly the simplest and cheapest way to accomplish the same thing, though, is to flux with the oak, and stir the pot with a (dry) pine, spruce, or fir stick, like the free ones you get at paint stores. The oak dust will handle the anti-oxidation tasks, and the heat will draw enough rosin from the stir stick for the actual fluxing.

[40Super]

Other wise take a pine log(if you can find one) to the sawmill and see if they will quickly turn it into sawdust for you. OR You can take a chainsaw or any sort of saw you have and go to town on the pine log yourself to turn it into sawdust. I keep all my 2x4 ,2x6, and 2x8 cutoffs from projects and convert to sawdust with my radial arm saw. I also pick up pine branches that break off from wind storms in the yard and cut them up in the sawdust pile. I prefer pine, smells better than the strong oak smoke. Apple trees works good also, smells better too.

[Bzcraig]

A friend owns a cabinet shop, though he does not use pine, I get a medium flat rate box full of oak saw dust which will last longer than me I suspect. Pine smells better but as said above it's the carbon produced that is beneficial. Avoid anything with glues or chemicals.

[PPGB]

The reason I mentioned the oak and cedar is because there are sawmills very near me that cut these woods and have large sawdust piles that I can get a 5 gal bucket full for FREE. I'll probably go with the oak, even though cedar doesn't bother me in the least, the neighbors may have some allergy to it.

Thanks everyone for the advice.