Hi there.
I have personally used this method so i know it works....that said to varying degrees depending on the state of deterioration of the exsisting sealer. Nevertheless you will see a marked improvement. You may need to repeat the process with the thinners more than once. Xynol thinners...
There are various suppliers. Use a search engine. Acrylic concrete sealer. 25 litre's will give yo what you need. I use Decorative Concrete UK. They will help you if you give them a buzz. Ask to speak to John. He will be able to give you some good advice.
Good luck
Hi there. If the sealer is acrylic based use Xynol thinners to remedy. Apply a liberal coating of thinners to the whole area. This should chemically react with the sealer bringing it back to it's liquid form. After 30 mins or so re-seal the drive with acrylic sealer. Hey presto. Job done.
i...
You have some valid points Mike. If i may i would like to correct some inaccuracies.
The concrete is PIC (pattern imprinted concrete) mix. This 10mm aggregate, fibre re-enforced with air entrainment additive. The rubber stamps are very expensive but can be hired for £100 per set, per week...
I find that using a diluted PVA bond 7 parts PVA to 1 water hepls. Brush the bond onto existing mortar (try not to overspill too much as cement will stick to it like **** to a blanket even on tne surface of a tile).
Whilst the PVA is still wet re-point the joints. Dont faff with the mortar...