Penetrating oils... Kroil, PlusGas, ChemAid by ChemEx, diesel or just WD40

Good Greetings ladies and gents,

I have two ways of looking at a small problem I have...with a seized block.

1) Penetrating oil doesn't seem to work  - every bolt I have used it on it only seems to get to the first couple of threads - when you eventually get the bolt of the rest are bone dry.

2) Penetrating oil does work - the viscosity of Kroil, for example is able to find gaps a millionth of an inch wide so creeps in nicely - the reason the nut is dry is the energy used to move it creates heat and that dries off the small amount of lubrication that had managed to penetrate the seized nut/bolt

my question to you fine people is - what does your experience tell you - do penetrating oils work and if so what do you recommend for a seized lister d.....

I know of Plus Gas, ChemAid by ChemEx, WD40 and diesel as the best in the Uk - Kroil is more USA - any others I should be looking at?

Best

Hamish

WD40 is not a penetrating oil its a water displacement fluid hence "WD"

the rest are ok but i find best is some paraffin , seems to be more oily than diesel , but hey why not mix diesel and paraffin together .

matt

My uncle swears by using old spice aftershave on siezed parts I had a jap shearing unit which was siezed and I put a drop in and it seemed to work very well. Matt

There was an article floating around a few years back about this. They did some scientific tests. The results were surprising in that ATF thinned with some solvent worked the best.

Myself, I don't have much faith in penetrating oil. Good for fixing squeaking door hinges, but they cant remove rust, and that's the issue. I think the growth of rust adds volume and forms a reasonable mechanical lock, and oil is simply not going to make that go away. For rusted bolts I use heat. Heat the bolt only red hot and let it cool. This causes expansion and contraction to break down the rust, and I have a very good success rate doing this.

[quote="pjjms"]There was an article floating around a few years back about this. They did some scientific tests. The results were surprising in that ATF thinned with some solvent worked the best.

Myself, I don't have much faith in penetrating oil. Good for fixing squeaking door hinges, but they cant remove rust, and that's the issue. I think the growth of rust adds volume and forms a reasonable mechanical lock, and oil is simply not going to make that go away. For rusted bolts I use heat. Heat the bolt only red hot and let it cool. This causes expansion and contraction to break down the rust, and I have a very good success rate doing this. [/quote]

I am inclined to agree with you on that one, heat works best for bolts and nuts, seized pistons I have soaked in diesel in the past and left to soak for ages and even then used heat to help release the piston in the end.

If the bolt/nut is that bad then I cut them off and start again, lot less agro as you know it will come off.

Just to add my two penneth worth, I have had great success with SAS spray , it has shifted the most stubborn of seized nuts and bolts in the past and always have a can in the workshop

Jon

im a mix it all together and see if it works "all things that engines will burn goes in new or old and a bit of heat every now and then for the expansion gap to grow and let some thing soak deeper and faster
atf is a very soak into oil ,get it on your skin and watch it soak in quickly "so yes i throw some old used powered steering oil from my old works van in ,seams to aid good results
as villiers says if its looking to break then just get it off if it snapps then just drill, extract, retap and fabricate a new
as somtimes its cost is lesser than the man hours to salvage it off
kev

Hi there,

I was having good success with an acid based penetrating oil, While I could get it!  Can't seem to find anyone who stocks it in Auckland, New Zealand now.
Now I use electrolysis, or if I can't get it in the tank, ie too big, or something (ie too impatient), I use ordinary penetrating oil or diesel or what ever is handy, tap with a hammer to help it in, FORCE, heat, more oil, more force, Jiggle it, find the right place for the tongue    More force, . . . eventually something has to give, hopefully not me!
If you can get the electrolysis at it it will come off with your fingers, (unless it was tight originally of course).

Cheers
Darryl

All very useful comments and feedback - I shall be putting all of these to the test with a stuck piston in the Lister D a fellow forum member donated to a local youngster/ engineer in the making very shortly... or rather the youngster can get his clothes stinking of diesel as its his from Christmas day onwards!

For Pistons stuck in the bore - fill the bore above the piston with COKE COLA and leave to soak for a week or 2 or 3............This can usually work.
I believe some people drink this!? Can this be good to drink??   

Good lord man, you can't waste coke like that!

Hmm - I like the thinking there Tony - and I/ my neighbours have an engine to try it out on - so watch this space.........

I have only restored 1 engine - a Lister D - but am working on another 2 - so have only limited experience in freeing bolts but I have used GT85 and heat with good results.Hope that helps.Kev.