I have. It was on an 8wt bamboo, but the double agate worked fine.

Not very traditional and not cheap, but it's fine. You're already going to single foot guides. I find it easier to wrap both sides of the snake guides than a single foot guide, but whatever you fine easier.

Do you have the agate guides in hand. A 12mm agate has a pretty small ID.

Carl

Double agate on a 9' 4wt is overkill in my opinion, i would probably go single 10 or 12 size. Also, might be just me but if you're going non traditional and using single foot, why go expensive and traditional on the stripping guides?

+1

Relative to 'glass rods and traditional manufacturing and building norms, the question would be better thought of as identifying the circumstances/configurations for which only one stripping-type guide would be used.

It used to be common--and at the same time when most fly rods were for lineweights 6, maybe 5, and up, and from the era before that when bamboo and the first fiberglass rods prevailed, that two stripping/casting/fighting/gathering guides were commonly fit. I think the reason is as simple as Kalgrm's term "fighting guides." Who knew, especially the manufacturer, what varied uses in a time of far less specialization of rod types, what use the rod would be put to: trolling for lake trout with rigs that themselves put more stress on the rod and guides than would be put on the same rod catching flippy-flop brook trout--and the same rod might very well be used for that purpose. Maybe some big Largemouth bass, explosive smallmouths, Atlantic salmon, west coast steelhead, and so on--not all by the same owner user, but in all the different markets where the rod might be sold and used.

In other words, a wider heavy to light duty range could be anticipated, so the "fighting" strength of two stripping guides was desirable.

So at one time, the default for a builder would have been two, and a choice would be made if only one would suffice. I have a favorite Fisher, built 30 some years ago with two stripping guides. I thought nothing of it at the time I built it, but eventually eyeballed that second one and wondered what good it was. I wondered why not replace that one (it did not need repair) with a snake guide. I never bothered since the rod, like several others I've built in that usual way, did exactly what I wanted of it.

Then one day I got into a spree of fall run browns five pounds and up and decided this failsafe configuration would stay as is.

On a little 4 weight, especially 'glass, two couldn't hurt, but I'd only use one, knowing I would not use the rod where outsize fish were expected. Agates as one stripping guide type are less critical as far as one or two. They are too dainty for my taste so I wouldn't use them regardless of the number of stripping/"fighting" guides going on the rod.

The cost and weight rationale is understandable but could you clarify the performance benefit? Good info.

I know many older rods used two or more strippers but I've never understood why. Seems to me the stripper closest to the reel will take 99% of the stress. Unless the rod is to be used for really big saltwater fish - and then probably all the guides should be beefier. Spoken from the perspective of a brookie fisherman

Thanks. Some days are slower than others