MTFCA Forum

OK, this brings up another straightening question. Would it be advisable to blast and leave unpainted before having it worked on or have it straightened before blast and paint? Thanks, Dave

Paint it later. Absolutely positively take your pan to someone with a pan jig.

Blast it first. Straighten the pan, and then paint. Do not sand blast the inside of the pan or a engine block or hogshead. The sand will in-bed in the pores of the metal and then the heat cool cycles of the engine will cause it to work out into your oil. The only way I would suggest that sand blasting the inside is OK is if you plan on using Glyptol to coat the inside. Also never powder coat a pan after straightening. There is a real good chance the heat from the powder coating will cause the pan to warp. Just think of the pan as a very tortured flat piece of steel that was violently forced into the shape of a pan. It "wants" to be a flat piece of steel again. any sandblasting or stress relieving heat from powder coating is helping it find its flat shape again ... Glass beads, "black beauty" or other slag type abrasive, or soda blasting is not bad about in-bedding in the pores of the metal, just regular sand.

have fun and be safe ........

[quote=dobro1956 post_id=19348 time=1553667370 user_id=457]Blast it first. Straighten the pan, and then paint. Do not sand blast the inside of the pan or a engine block or hogshead. The sand will in-bed in the pores of the metal and then the heat cool cycles of the engine will cause it to work out into your oil. The only way I would suggest that sand blasting the inside is OK is if you plan on using Glyptol to coat the inside. Also never powder coat a pan after straightening. There is a real good chance the heat from the powder coating will cause the pan to warp. Just think of the pan as a very tortured flat piece of steel that was violently forced into the shape of a pan. It "wants" to be a flat piece of steel again. any sandblasting or stress relieving heat from powder coating is helping it find its flat shape again ... Glass beads, "black beauty" or other slag type abrasive, or soda blasting is not bad about in-bedding in the pores of the metal, just regular sand.

have fun and be safe ........[/quote]


Fortunately this has NOT been my experiences.

Fortunate on this '26 pan, cleaned, painted and Glyptol'ed the inside. Had checked it manually on my home garage 'pan checker', made from an unusable '26 block, bolted to an unusable '26 hogshead. Those 2 block to hogshead bolts makes a good tight combo with the full flat surfaces to 'check' a pan for gross out of whack.

Then took the finished pan to another T'er who had a KRW jig, to do the final check/adjusting, didn't need any more attention, everything luckily lined up

Brent. I know of enough cases where a fresh straightened pan has warped enough to need re-straightened after powder coating. Its not like they were as bad as before they were originally straightened, but enough that the pans would not fit back on the pan jig without some rework. usually enough to really mess up the new powder coat. A small home sandblaster with limited air pressure may not be enough to cause a problem, I have never used a small blaster with limited air pressure to know for sure. I have a 185cfm beast that I blast with. It is the size of most commercial blasters. It will change a newly straightened pan. If a person uses a commercial blaster, then it will also probably change the pan. That is why I now blast before and straighten later. but as most of the things we all work on. mileage may vary for different folks. I may just be the un-lucky one most of the time ...

have fun and be safe ...