oooh,oooh me,me,me mr isle of manky i have had two chassis galvanised, what do you want to know
Anyway, back to painted on rustproofing
1: Strip it all down so there are no melty things i.e bushes etc on the chassis2: Get it shot/sand blasted to find all the holes and remove the surface rust on the outside3: Repair all the holes you have just found4: Blow it out with an airline as you have now filled it with sand/shot and bits of grinding dust5: Get rid of any underseal that is there otherwise you will make a mess of the galv and they will have to dip it twice and pay twice 6: Take it to the galvanisers who do the restYou are looking at about £100 for the shotblastunlimited £ssss for repairscost me about £200 +VAT for the galv part at the beginning of the year.Oh and you will need a selection of taps and files to clean out the threads and mounts that are now full of zincYour problem is you need a galvanisers and i assume there isnt one on the Isle of Manhttp://www.wedge-galv.co.uk/default.aspxoh and scrw since this thread has gone awry as usual i found that the underbody sealer stuff with waxoyl seems quite good.http://www.hammerite-automotive.com/
Zinc primer spray...followed by some Rustoleum