Touching Up Problem Spots on Stained Floors

Problem areas that will not take stain.

Question:
How do I fix areas on acid stained floors where the color has worn away? I also need advice on touching up spots that did not take the stain at all. I tried spot staining them and it only made them look bleached. The floors have not been sealed, only waxed.

Answer:
Trying to spot treat with stains often leads to bigger problems than those you started with. Staining is a process that works much better over larger surface areas because it looks more natural then small spot treatments.

To help correct the problem areas you describe, proper surface preparation and pretreatment are necessary. First, I recommend conducting a water-absorption test by spraying a fine mist of water over the surface prior to staining to look for areas that are darker or don’t absorb the water as readily. To help open the slab and create a surface that will take the stain more uniformly, try dry sanding using a rotary sanding scrubber with 150-grit paper, or applying a chemical pretreatment such as QC Con-Clean (available from QC Construction Products).

It’s always best to treat problem areas prior to sealing and waxing. If a sealer or wax has been applied, you can mix tints (either water- or solvent-based, in a color to match the stain) into the sealer or wax and then reapply to the small problem areas and blemishes.

The last, and most important issue, is proper maintenance. The worn areas on the floor are likely due to lack of a protective sealer. You should always apply a base coat of sealer followed by a sacrificial topcoat of wax. At the first sign of wear, the wax should be reapplied to maintain a good wear surface.