even coat

The problem areas on your table are probably caused by surface contamination from oils, waxes or cleaning products used over the years.

Contaminants from dusting sprays that contain silicone will also impact the appearance and adherence of a finish - silicone is almost impossible to remove. Oil soaps and wax can also cause adhesion failures. This may be why the finish is performing differently on the leaves vs the table top. Adhesion failure is often more obvious in the deepest patterns of grain because the contamination is driven deep into the grain. 

Unfortunately, even though you sanded the table down to raw wood, sanding alone will not remove this type of contamination. In fact, sometimes the friction heat of sanding will drive contaminants deeper into the grain. 

You have two options, and we recommend the first:

1. Strip, sand and refinish the table. Use a strong solvent such as a paint stripper and, brushing the surface with a soft brass brush to clean out the grain. Follow this by cleaning with 0000 Medium steel wool and mineral spirits.
2. Buff the existing finish with 0000 steel wool and mineral spirits, particularly in the affected areas, and then re-apply several more coats of Arm-R-Seal

While Gel Stain can be applied over an existing finish, it was originally engineered for raw wood surfaces. We prefer applying the Gel Stain over a slip coat of mineral spirits instead of topcoat as shown in this video, "How to Apply Gel Stain to Raw Wood"

The slip coat will reduce the drag and help the stain "glide on" easier. The other important technique shown in this video is to apply the stain liberally in sections and remove the excess quickly. Gel Stain is so pigment rich you will get an uneven application if you try to dab it on with a dry rag.

Applying over a layer of top coat is acceptable, but there are two big benefits of applying the stain directly to the wood or over a slip coat.

1. The beauty of the grain is highlighted. This effect will be greatly diminished if the stain is applied over an existing finish.
2. Less coats are required to obtain a dark color.

Preparation and application techniques along with dry time between coats are all different when applying Gel Stain over raw wood vs. an existing finish.

Dry time differences