If you have some putty, some of that stuck around each of the plug welds before welding. That would act as a heat sink to keep the weld heat from going too far afield. I think there's specific putty for that use, not something that is oil based, which might ignite.
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.