Penetrating oil recommendations for vintage saw repairs

[Ansem_Darkness]

Picked up a Stihl 020 AVP Professional (West German build) for $35. Compression is solid, but no spark, so I'm planning to pull the ignition coil and try baking it. Got most of the screws out of the recoil cover, but one is frozen solid. It's been sitting overnight in PB Blaster without any luck. I'm debating whether it's worth picking up a can of Kroil specifically for these situations. Some folks swear by it, others say it's not much better than what I'm already using. Anyone here have firsthand experience with Kroil on stubborn fasteners in old saws? Does it actually make a difference, or should I just break out heat/impact and skip buying yet another can of penetrating oil?

 

[Helios guy]

Let it soak a bit, then you can use heat usually frees it up without rounding the head.

 

[CaptTurbo]

Picked up a Stihl 020 AVP Professional (West German build) for $35. Compression is solid, but no spark, so I'm planning to pull the ignition coil and try baking it. Got most of the screws out of the recoil cover, but one is frozen solid. It's been sitting overnight in PB Blaster without any luck. I'm debating whether it's worth picking up a can of Kroil specifically for these situations. Some folks swear by it, others say it's not much better than what I'm already using. Anyone here have firsthand experience with Kroil on stubborn fasteners in old saws? Does it actually make a difference, or should I just break out heat/impact and skip buying yet another can of penetrating oil?

Surprisingly, the venerable Liquid Wrench stood tall among the penetrating oils tested by "The Farm Guy" who is a well respected YouTube poster with a huge following. PB Blaster didn't make the top rating which was a surprise to me.

 

[Gary]

I have used it and found it nothing special ! was a heavy equip. mech before retiring !

 

[CaptTurbo]

I have used it and found it nothing special ! was a heavy equip. mech before retiring !

Used what?

 

[Doug Balko]

Make a 50/50 mix of acetone and transmission fluid. No promises but has worked good for me and I'm guessing you have the ingredients on the shelf?

 

[Paul]

Stepson is a millwright
Swears by the acetone, tranny fluid mix.

 

[John Walsh]

Make a 50/50 mix of acetone and transmission fluid. No promises but has worked good for me and I'm guessing you have the ingredients on the shelf?

I'm with the responders who recced the acetone/ATF mix. I have used it many times on really stubborn fasteners if bolt or stud into aluminum. If bolt and nut and can use oxy/acetylene w/o ruining adjacent stuff, I use that.