• The site migration is complete! Hopefully everything transferred properly from the multiple decades old software we were using before. If you notice any issues please let me know, thanks! Also, I'm still working on things like chatbox, etc so hopefully those will be working in the next week or two.

DIY: How to polish engine parts

03GPScottyd

New member
First off I would like to say that I got this from SupraForums.com.au and it was written by Solman, but if you plan on using this writeup you have to pay me a finders fee of at least one polished part for my car. I figure if 20 of you use this writeup, my whole engine should be showcar ready within the year. :th_biggrin2:

Disclaimer: I have not tried to do this but it should be common sense that if you attempt to do this you could remove too much metal and make the part that you are attempting to polish structurally weaker and it could fail in the future if you are not careful when attempting this process.

DIY: How to polish engine parts:

This is a guide on how to polish engine parts. An intake manifold is used to show how, but this can be done on just about any metallic engine part (piping, cast aluminum, sheet metals and others)

Before:
3094121_26_full.jpg


After:
3094121_27_full.jpg


Tools require and costs:

Brown Buffing soap $10 approx
White buffing soap $10 approx
Loose buffing wheel $20 approx
Stitched buffing wheel $20 approx
3094121_5_full.jpg


Bench grinder $50 - $300 depending on brand
Adapter for wheel $20 approx
3094121_6_full.jpg


Angle grinder $50 - $300 depending on brand
120grit sanding disk $15 approx
3094121_7_full.jpg


Wet and dry Sand paper:

2 x 120grit $2
2 x 240grit $2
1 x 400grit $1
1 x 800grit $1
1 x 1200grit $1
1 x 2000grit $1

Disposable gloves $7 approx this is optional just makes it easier to keep hands clean


Step 1 Tape (Optional):

Tape up intake manifold to avoid aluminum bits getting inside it while sanding. Still clean it out with degreaser once your done, this just makes it easier to clean afterwards.
3094121_8_full.jpg



Step 2 Using the angle grinder:

The manifold is a cast aluminum part so there are lots of “pores” that need removing. Other metal parts may not require this level of sanding as they are relatively smooth all ready.
3094121_9_full.jpg


Ok some people may be afraid to take an angel grinder to their engine parts, but the sanding disk that is used is fairly fine, so it should be ok as long as you don’t sit there for half an hour on one spot. Apply light even pressure and “brush” it along the part.

If your really worried skip this step, but if your sanding down cast aluminum like the intake manifold, then either your patient as hell or you will reconsider.
3094121_10_full.jpg


You want to make sure you remove all the pores!
3094121_11_full.jpg


After using the grinder you will end up with something like this:
3094121_12_full.jpg



Step 3 Manual sanding:

Ok now that the pores are removed we need to smooth out the surface. Use the same grit as the disk here (120grit) to even out the lines and unevenness left by the sanding disk.
3094121_13_full.jpg


After dry sanding, spray some degreaser and then do a wet sand which gives a better finish.
3094121_14_full.jpg


3094121_15_full.jpg


This is how it looks after the wet sand:
3094121_16_full.jpg


Continue doing the same with 240, 400, 800, 1200, and 2000 grit.

After 400 grit:
3094121_17_full.jpg


After 800 grit:
3094121_18_full.jpg

You should be able to see it becoming more reflective.

After 1200 grit:
Here you can see the difference between a wet and dry sand (top being wet)
3094121_19_full.jpg


And Finally after the 2000 grit:
3094121_20_full.jpg



Step 4 polishing (cutting stage):

Ok now that the hard part is complete all we have left is to polish the surface. The finish of your product will depend on how much effort you put into your sanding, and the smoother the sanding the better the polish.

Setup your bench grinder with the tapered tool and the stitched wheel, this wheel is a cutting wheel which “cuts” the material to give it a better finish.
3094121_21_full.jpg


Use the brown buffing soap with this wheel.
3094121_22_full.jpg


Take your time and try to work every area. Make sure you reapply more buffing soap on your wheel now and then.

This is the finish product after the cutting wheel.
3094121_23_full.jpg



Step 4 polishing (Final polish):

Ok now change the buffing wheel to the loose buffing wheel. Use the white buffing soap with this wheel to give the metal a better overall finish.
3094121_24_full.jpg


This is how it should look after this stage:
3094121_25_full.jpg


Now get out there and polish away.
 
Last edited:


Looks good. :th_thumbsup-wink: Nice find.

He forgot to add in how long it takes, how bad breathing aluminum dust is, and how big of a mess everything makes. :th_sick1:

But if you take your time, and make everything smooth sanding, then the end result is smooth as glass and reflects no flaws.

~F~
 


I love to do stuff myself. I bought a motor, buffs, bits, bobs, sanding cones and compounds. After about 28 hours and little reward, I found it's MUCH satisfying to go through Farnsworth. :)
 


Back
Top