Announcement

Collapse
No announcement yet.

restoring and painting air cooled engine cylinders and other engine components

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • restoring and painting air cooled engine cylinders and other engine components

    What is the best practice for cleaning and painting these things?
    Or is it even recommended? Maybe best to not touch it?
    Completely out of my wheelhouse here...
    Cheers,
    Jon
    Attached Files

  • #2
    While not exactly the same beast, on a twin cylinder air cooled 2 stoke engine, I bead blasted the jugs and heads clean and then painted with PJ1 satin black engine paint.

    This was of course fully disassembled.

    Comment


    • #3
      Originally posted by oxford View Post
      While not exactly the same beast, on a twin cylinder air cooled 2 stoke engine, I bead blasted the jugs and heads clean and then painted with PJ1 satin black engine paint.

      This was of course fully disassembled.
      This thing seems tight and ready to run so I dont intend to disassemble it.
      I have a cheesy pneumatic sand blaster with a hopper, I guess it will work with beads or walnut shells to eh?
      Cheers,
      Jon

      Comment


      • #4
        Originally posted by Jon Heron View Post

        This thing seems tight and ready to run so I dont intend to disassemble it.
        I have a cheesy pneumatic sand blaster with a hopper, I guess it will work with beads or walnut shells to eh?
        Cheers,
        Jon
        I’ll admit, the ones I did were a pain in the ass. Whatever the factory used for paint stuck pretty well and trying to get deep into the fins didn’t help.

        Comment


        • #5
          I wouldn't suggest bead blasting it assembled as that crap will get into places you'll never be able to see or clean and may lead to problems down the road.
          I can understand not wanting to pull the jugs just for cleaning and painting. Wire brush them as best you can and use a high temp engine enamel.
          Avoid any heavy paint build up on the fins as it may lead to poor heat dissipation.
          I've used round wire brushes to clean between the fins. Find a size that fits good. You can even spin them on a drill.

          JL...............

          Comment


          • #6
            Originally posted by oxford View Post
            While not exactly the same beast, on a twin cylinder air cooled 2 stoke engine, I bead blasted the jugs and heads clean and then painted with PJ1 satin black engine paint.

            This was of course fully disassembled.
            Yes I've always done pretty well much the same. An abrasive blast not only gives the paint something to adhere to but also leaves a nice newly sandcast texture to aluminum for those pieces that you don't paint, or don't want painted.
            I've seen air-cooled aircraft engines with both painted black cylinders and with just a bead blasted finish and they both look good to my eye, purely subjective I suppose.

            Ensuring there are no fluid leaks will leave the surface looking good for a long time. I have some engines done this way decades ago and they still look pristine.
            Masking areas that you don't intend to blast is a big helper as well as making sure that you don't get any media in the internals is paramount.
            Home, down in the valley behind the Red Angus
            Bad Decisions Make Good Stories​

            Location: British Columbia

            Comment


            • #7
              I am certainly not an A&P, but as I understand it, you really do not want to "just pull the jugs" on that.

              It's not difficult, but there seem to be "details" A lot of those engines have un-keyed bearing shells, kept in position by "crush". Apparently they need to have the long through-studs tight, or the shells can shift and block the oil ports. That seems to be one fairly "common" cause of failures in the air soon after an overhaul.🤔

              Best practice seems to be not having more than two jugs off it at a time, unless the through-studs are tightened again after removing a pair of jugs. An A&P (we have a few on here) may be able to confirm the right process.

              Your engine will never fly again, but even on the river a failure would not be good.
              2730

              Keep eye on ball.
              Hashim Khan

              Everything not impossible is compulsory

              Comment


              • #8
                Originally posted by JoeLee View Post
                I wouldn't suggest bead blasting it assembled as that crap will get into places you'll never be able to see or clean and may lead to problems down the road.
                I can understand not wanting to pull the jugs just for cleaning and painting. Wire brush them as best you can and use a high temp engine enamel.
                Avoid any heavy paint build up on the fins as it may lead to poor heat dissipation.
                I've used round wire brushes to clean between the fins. Find a size that fits good. You can even spin them on a drill.

                JL...............
                Personally, I wouldn’t blast it assembled either.

                I’d either do the suggested above with wire brush, disassemble, or leave alone.

                Comment


                • #9
                  Airworthy engine or for another use.
                  If airworthy you might want to see if an approved paint is listed as heat rejection is critical.

                  Comment


                  • #10
                    I see some corrosion on the fins.
                    Glass bead / sand blasting can be deadly to an engine.
                    If you try to tape everything off, I bet you still get sand in
                    the oil. Dremel tool with a bunch of those itty bitty wire
                    brushes that fit in between the fins is probably the best
                    way, without taking the jugs off and blasting them independently.
                    I cleaned a motorcycle engine with a Dremel and wire wheels
                    one time. It came out great, but took a bunch of time. The
                    factory engine paint was in really good condition, only the
                    cooling fins had dirt and corrosion. It came out nice and all
                    it took was patience.

                    --Doozer
                    DZER

                    Comment


                    • #11
                      As many have noted - do NOT GET a media blaster anywhere near an assembled engine, ever.

                      Comment


                      • #12
                        Originally posted by oxford View Post

                        Personally, I wouldn’t blast it assembled either.

                        I’d either do the suggested above with wire brush, disassemble, or leave alone.
                        I've used the round steel wire tube brushes. They come in every imaginable dia. with different length wire stems / shafts. Spin them on a drill and they will clean up the fins better than bead blasting will. Blow the dust out, wipe them clean rag wrapped around a paint stick and prep-sol and your ready for paint.

                        JL...............

                        Comment


                        • #13
                          Used with discretion a media blaster is not the kiss of death as some would purport it to be. Make no mistake used on internal components or otherwise allowed ingress to the internals it certainly can be as it can embed itself and be the cause of an early demise of an engine's life.
                          However given the fact that many have used this method of cleaning external engine assemblies and or components successfully far too many times to count, including myself, it is still a very viable and time effective method of restoration.

                          Personally I can't see myself doing the slow archeologist's method of cleaning the depths of each fin with a tiny wire brush. Maybe with the aid of a chemical stripper it may be an option.

                          If abrasives used externally were indeed the kiss of death would someone please explain to me how engines restored this way have lasted thousands of hours of use in very hostile and abrasive environments. I can't think of how many thousands of pounds of abrasive sand and dirt some of my dirt bike engines have endured while constantly being pelted with grit from the front wheel. The street bike too has well over a 100,000 miles of dust and road debris thrown at it for decades.
                          Air-cooled power equipment also sees more dirt laden air blasted onto it's cylinders and heads to cool the engine than clean air.

                          Yet a media blaster is the kiss of death?
                          I think much of this is anecdotal folklore based on those that may have either blasted an engine's internals on purpose to clean baked on carbon/varnish or it got in due to carelessness.

                          As with any other tool, inappropriate use will do more harm than good.
                          Home, down in the valley behind the Red Angus
                          Bad Decisions Make Good Stories​

                          Location: British Columbia

                          Comment


                          • #14
                            Never Powder Coat anything that needs expel heat engine Fins or Liquid Heat Exchangers.

                            Comment


                            • #15
                              would dry ice blasting work for this?

                              Comment

                              Working...
                              X