Along time ago, we used a barn attached to a friends house as a garage, my mate was rebuilding an old Austin Healey, he used to nip into the house & put the underseal in the oven. One day he forgot to take the lid off ......... Half an hour later & bang, lid off & the inside of the oven! Well put it this way, it never went rusty after. Took him a couple of hours to clean out the mess, & the housewife in a huff for ages.it might need thinning I usually stick the tin on the hob for a while until its hot then thin with some white spirit