Many of us have used sac oil mixed with castor to trap beaver, however I would be interested in hearing accounts from those that use pure sac oil and nothing else and how that compared to using straight castor. It has been noticed by me that many recommend sac oil as a change up, or to catch a castor shy beaver. Anybody use pure sac oil the whole season?

Never have but I'd be down to experiment with it next season. I'm not giving up my go to bait but why not give it a go. You're a much more experienced beaver trapper than me but what do I have to lose?

It works great! I use it on those sharp beavers that have an aversion to lures. It can be used all season long too. It doesn't take much either. I like to make a small slick spot on the bank and using a pine needle, or other small twig, I dip it in the oil and only dab it on the slick spot in three or our places. Then I throw the stick/straw into the water so the oil will spread out leaving a trail on the surface. It doesn't initiate a territorial response. I usually set a foothold for a front foot catch. I don't use 330s, because most of the beavers I use this on are already educated. This is one of those tricks my pappy taught me.

Make three sets side by side-one with castor and one with oil from the stones and one with regular castor mix with oil from stones..
See which one or if all three catch a beaver overnight.

I used cat lure with sack out for beaver one spring. I was working a coyote job and the rancher asked ne to trap a colony of beaver. The lure was Vicks menthol rub sac oil and some catnip. It worked fine it was all I had with me at camp.

I strip the oil and then grind the sacs and mix with grease, I like it on a stick with part of the lure in the water, or on a paper towel. I want the lure to be in the water a little.

Have used sac oil for years and can't tell a difference in effectiveness from store bought lures. Use it year round.

I used sac oil only for probably the last 5 years doing control work. I agree with Paul that it doesn't cause an "attack" response. I started using it when castor prices went up, and I happened to have a discussion with another trapper about sac oil. He said to keep the male oil separate from the female oil. I always did that, but never did think that it made a difference. Both oils attracted both sexes. I did usually use conibears, but also usually used existing slides. I always rigged so the trapped beaver was well away from the set. I had dozens of locations that produced a half dozen beaver.

How well does sac oil store? Can it be used next season? Add sodium benzoate?

I save sac oil as a last resort lure. It has always worked when everything else has quit working. I'm not positive castor or any other lure would work as well after the beavers have been messed with a few days.That natural smell at a natural location usually closes the deal.

One little drop is all you need.

I use sac oil more than castor or even castor lures. It works just as good and even better in some situations.

Sac oil does seem to spoil, but I have used it like that, and the beaver didn't care. I never added anything to it. I was always good as long as it lasted. Every beaver has some, so not hard to come by.

I used to mix up poplar chips and some sac oil to refresh sets on some of my lines on the Oregon coast. It was really easy to use as I just reached into the bucket, grabbed a handful of chips and threw it on the other side of the 330. Got excellent results.

Used sac oil when they became shy to castor in ponds worked very well

Don Nichols did a demo I watched once. He said the only lure he used was sack oil. Castor was worth to much. He also said the same thing Paul says about the response. Don also said if you missed in one set they did not seem to be leary fo the sack oil in another set.
Years back I targeted nutria. I had one basic set when first setting up. It was a pocket set with a fairly deep step down made high on steep banks so it stayed active in rising waters. Every set got tail oil. I used a no2 trap. Caught a bunch of beaver with the nutes and no need for downers as it is pretty hard for a beaver to chew out of a trap that small.
Ted

good read guys thanks, I've tried oil sack and it work.

I use it very lightly in my castor lure recipe

And stand alone attractant on tough final beaver

Usually sac oil from one of their own colony.

Beaver do not chew out....they twist after tangling the trap.

Thanks for the clarification SW. I'm no beaver trapper and that one had me scratching my head.