I have a Modle A Ford that needs its gas tank sealed. The tank doesn’t leak, it is just rusty inside. Since the tank can not be removed from these cars, I was wondering if your gas tank sealer (part # 10565zp) could be applied using the same spray gun that is included in your Rust Proofing/ Under Coating System. (part # 16003) I understand that the tank will need to be thourghly cleaned with muriatic acid, acetone, metal wash and oxisolv. Would it be possible to simply fill the tank with these cleaning solutions and agitate for a period of time before draining? Any advise you may have will be appricated.