Wax free seal on rusty flange?

[Rocknroj]

apologies if this already answered. I did look. I have an old cast iron flange and perhaps some floor flex. Considering the Danco although the fluid master looks better for my application. The flange is not quite level and goes from about 1/8 below finished floor in front to about 1/4 below in the back. The finished floor itself is pretty darn level. All the Danco vids show use on ABS or PVC. Same with the other products.

Will any of those rubber seals work on old rusty cast iron? I can clean, scrape, wire brush, sand, whatever.. Still gonna be a pitted surface. Yes I know there is a wax piece in the Danco.

One option I have been considering is using a plastic spacer, seal it with silicon and bolt it tight so I have a clean smooth surface for the gasket. Will the silicon stick to the rusty surface?

Question.. On the Danco.. remove the blue? The black plastic on the bottom? It really looks like it would be too high to get the toilet to sit.

The Fluidmaster better than wax actually looks better to me, perhaps with a spacer carefully attached and sealed to the old cast iron?

I am asking because I anticipate and perhaps can feel some floor flex. Its an old house and destined to be a rental that I don't want to visit when done.. Learning a new trick would not be bad either. I have installed a few toilets, always going to the wax ring, often (more often than not) stacking. A neater method would be nice as I always have a mess to clean. Usually I take 2 sets of rings, stab the toilet and if it doesn't feel right, pull it up, change out the wax and try again..

I tried one of the twist-n-set varieties on another property, also CI, but getting a seal against the rust stuff seemed impossible and in fact lifting the toilet lifted out the twist-n-set from inside the pipe.

Ok thanks for the input. I am expecting trial and error here as is usual with something new to me.

I am expecting its either stacked wax or the Danco without the blue piece if I can get it to compress. Too bad their instructions are so weak..

 

[Rocknroj]

apologies if this already answered. I did look. I have an old cast iron flange and perhaps some floor flex. Considering the Danco although the fluid master looks better for my application. The flange is not quite level and goes from about 1/8 below finished floor in front to about 1/4 below in the back. The finished floor itself is pretty darn level. All the Danco vids show use on ABS or PVC. Same with the other products.

Will any of those rubber seals work on old rusty cast iron? I can clean, scrape, wire brush, sand, whatever.. Still gonna be a pitted surface. Yes I know there is a wax piece in the Danco.

One option I have been considering is using a plastic spacer, seal it with silicon and bolt it tight so I have a clean smooth surface for the gasket. Will the silicon stick to the rusty surface?

Question.. On the Danco.. remove the blue? The black plastic on the bottom? It really looks like it would be too high to get the toilet to sit.

The Fluidmaster better than wax actually looks better to me, perhaps with a spacer carefully attached and sealed to the old cast iron?

I am asking because I anticipate and perhaps can feel some floor flex. Its an old house and destined to be a rental that I don't want to visit when done.. Learning a new trick would not be bad either. I have installed a few toilets, always going to the wax ring, often (more often than not) stacking. A neater method would be nice as I always have a mess to clean. Usually I take 2 sets of rings, stab the toilet and if it doesn't feel right, pull it up, change out the wax and try again..

I tried one of the twist-n-set varieties on another property, also CI, but getting a seal against the rust stuff seemed impossible and in fact lifting the toilet lifted out the twist-n-set from inside the pipe.

Ok thanks for the input. I am expecting trial and error here as is usual with something new to me.

I am expecting its either stacked wax or the Danco without the blue piece if I can get it to compress. Too bad their instructions are so weak..

Figured I would update this myself since the job is done.

So I used the danco perfect seal.. Some trial and error and I placed the toilet several times. What finally worked for me was carefully seating the wax seal by hand. The reinforcement ring was enough to maintain the shape as I worked it down by hand to seat into the old flange. I was able to verify that the wax filled the recess in the old flange and just squeezed around the horn of the wax ring.

I would say that the first 'stab' at it with the blue extension did not seem like it would work. Then without the extension it did not seem like enough pressure had been applied. Indeed the danco just lifted out and had barely made a dent in the wax. It was only after working the seal down by hand so that the wax was well compressed that I got it to work (or at least for now). Once I had the wax ring seated, I tried without and with the blue extension. Ended up using the extension. The force required to compress the rubber components was minimal but there was some resistance, enough to make me feel comfortable.

Most of the compressive force required to install the thing is to compress the wax ring as described above. Simply placing the piece and tightening the tank bolts did not compress the wax ring. I am guessing that just compressed the rubber pieces. Probably the reason that many have trouble with this product. Danco should update their instructions (jmho). I did notice that the blue extension piece was nicely adhered to the toilet outlet when doing my dead lifts.

The other thing that is noteworthy about this product is that there is still a wax ring, and willy nilly moving the toilet around seems to me could result in failure. To reposition the toilet one must carefully loosen the tank bolts to allow a vertical lift of the toilet without twisting the lower portion with the wax seal.

When done I poured a bucket of water in the bowl, checked for leaks and all appeared to be good. Will see today if the bowl is still full.

So it took a while with the new to me product but the lessons learned will help on the next project. I will probably use the danco again. Not having to clean my wax mess is a bonus.