If you follow the instructions and utilize the Fast Etch then stop there at that point until you are ready to proceed. Then use the Acetone and Muriatic acid as stated and proceed. Fast Etch leaves behind a temporary protective coating to prevent flash rust.

The existing sealer would need to be removed first by following the below steps; then replacement sealer can be used to re seal. Use regular acetone or MEK (Methyl Ethyl Keytone) and fill tank ½ way with either chemical. Keep lid on, agitate and shake periodically. Leave in tank for 24 hours. The more it is agitated, the more success you will have. Don’t let it sit. Remove lid and inspect tank. Pour the acetone or MEK into a reusable container. CAUTION – Acetone or MEK will harm the paint on the tank. You can use Petroleum Jelly or Vaseline on the outside of the tank to protect paint. Acetone or MEK will dissolve liner back into a liquid form. If liner is still adhering to the tank, pour acetone or MEK back into the tank and re-seal and repeat process until it is completely removed. This can take 3-4 days.