I've got this nice, new Edelbrock intake manifold (natural, cast finish) that I'd like to grind off the "Edelbrock" and the "Made in USA" logos off of the front runners. Any ideas on how to re-create the "cast" surface texture on these small areas that are now ground smooth? Can you maybe brush on some kind of acid on the areas or is there some other method anybody has tried successfully?
You need a carbide style bit for a die grinder. What you can do is to let it gently "dance" over the ground surface. Practice on the back side to get your groove on and I think you'd be surprised how natural it looks once done. After that you can wash it all down with something like naval jelly or Aluma-prep for painting aluminum. The other way is to get it nice and level then have the intake shot peened by a reputable shop. Tape off all the machined surfaces and have at it. Looks like a new intake in a very short time. Again best to try it on something else to get the gig down. I've done both with great results.
Blasting will cover the grind marks if they are not to deep. Go easy with the grinder. the trick is to bring the surface to a smooooth look...blasting will take care of the rest.
I remember an instance where a certain shop was trying to get the original cast finish back on an engine block that had been polished.Sandblasting and bead blasting were tried to no avail.One of the techs came up with a solution:make a,"chasing"tool(similar to a punch with random surfaces carved into it)and literally hand hammered(chased)the entire engine ***embly.You might want to check with alfin32(HAMB name)on here;it was done in the shop he works in.
I've helped do that with a piece of grinding disc, like 36-50 grit, and a hammer. Tap the disc around then dress with a super gentle blast.
I grind them fairly smooth and then use the heavy grit( 36 or 24) sand paper or grinding disc and a hammer moving paper to keep from showing a pattern. works good, no need to blast just blast area with carb cleaner and should be good to go again .
Read an article in VETTE magazine years ago on repairing aluminum intakes. Said to peen the area with a air powered needle descaler then put acid (I believe muratic) on it for just a minute or so and the acid etches the aluminum to perfectly match the original finish. If I can find the article i'll try to scan it. Jim
This is great...I have a weathered Edelbrock 553 that had a whole drilled in one of the runners for a vaccuum source...was wondering how to blend it in after it was plugged without having the manifold polished... Great tech info! Thanks guys...
I have had good luck using the rough grit sandpaper and hammer trick as well...I recently did this same thing on an older performer RPM . I ground off the lettering and drilled it for an oil fill tube. After I did the sandpaper trick I used aluminum oxide (I think) in my gl*** bead cabinet...this material is alot more aggressive than gl*** beads (or anything else I've found) and really adds to the "as cast" look...it completely eliminates any "smooth" looking spots... sam
Ding Ding! I've done this many times. I learned it from old timer that said he did a lot of motorcycle cases this way back then . You can vary the grits for finer marks. You can also use a bull nosed body hammer or a dull punch to get started then follow with the paper/disc and hammer.
Milkweed is on the right track. I've tried a bunch of different ways and always had best results with the needle scaler. You might have to sharpen the neeles up a little, just depends. You want them to be kind of sharp. You can vary the depth and texture that you get by increasing the pressure that you apply to the scaler and also by adjusting the air pressure. After the scaler I usually apply a little muriatic acid to the whole intake then bead blast or shot peen the whole thing to get an even finish.
I do this everyday on many of the parts that I make and as stated above shot peening will come real close to the factory finish. You can buy a small box of steel shot at your local china frieght store and put it in a blast cabinet. Crafty
I've used 40 grit Aluminum oxide on the inside of intake ports to get that "as cast" finish on race heads. It was good enough for "tech inspectors". Just vary the air pressure and/or the distance from the surface as you move around on the part. Use a small nozzle to get a close pattern. Should do the trick.
Broken drill bit (around 1/8 inch) in a drill or die grinder at about 45 degree angle to material. Also works good for cleaning edges of weld seams to brite clean metal that grinder misses (low spots) before bondo or lead. I use this method to get the cast steel look back on reworked (re-welded) door latch strikers for early Fords. Let it bounce around a little.
I worked for an aluminum casting company a few years ago. When they had to rework their castings, after the welding or grinding process, the castings were put into a steel shot wheel abrader. It used cast steel shot about 3/32" diamater. A lot of these parts were used in the auto industry.
The water neck in this photo was a smooth polished part when I started. I went over it with a needle scale tool and then sand blasted it to take some of the sharpness out.
Sandpaper and a hammer is what I use. Different grits to match the different casting roughnesses. Light gl*** bead over that to blend it in.
I had a faux QC for an 8.8" that had to be modified. I used a pneumatic scaler to refinish it after welding on the correct flange
Notes from 2015 Moon Discs... small wall disc to spun aluminum dish with cover My most fun moments came from using a industrial size lathe in college, that was part of an art elective cl***. It was the most fun cl*** I ever took in all of my college years. (except for the one cl*** where I met my wife.) My goal was to be able to make a Moon Ddisc for household wall decorations. I learned the proper way to make the pattern, use the shaping tool and create some interesting pieces. The large Moon Disc looked good, but compared to the original versions, not so much. Eventually, I got an “A” because I took the large disc and made a 7 inch domed lid for another spun aluminum matching disc bowl. It was a coffee table candy or other necessary items that could be covered and put on display. The two spun items were dipped in some custom art designs using rubber cement and acid. Hello, When I was a senior in college, I needed several elective cl***es to fill up my quota of credits for graduation. One of the electives was a cl*** called “Art Metal.” It was an art major cl*** and we simple folk usually took it because we were told it was the most fun cl*** in school. Boy, was it ever…the most fun cl***. Yes, I could have taken this cl*** every semester for all of the years and loved every minute of it. We made all sorts of projects from jewelry to bowls, to boxes to wall decorations. One of the girls was doing a simple candy dish out of a piece of aluminum. She made the mold out of wood and clamped it into the lathe. Then with the instructor’s directions, she used a tool that looked like a long, flattened s**** to gently rub the flat aluminum circle into this rounded wooden mold. By the time she was finished, I thought I could make a spun Moon Disc for a wall decoration. It was not going to go on a car, (could be with extra tooling) but on our apartment wooden wall. So, I followed the list of prep items, got everything together and started to cut the larger aluminum disc. My wooden mold was around 12 inches across with a slight convex shape. All I had to do was to spin and shape the flat aluminum onto the wooden shape and I would have a spun aluminum copy of a Moon Disc. Pro Version our version was a smooth wooden convex shape on the left with a small aluminum sheet in front (courtesy of the Douglas Aircraft Surplus Lot in Lakewood.) Jnaki It was not as simple as the candy dish because the shape was not to curve the edge up to create a lip. The wood shape was thinner as the edge of the disk was reached. I destroyed several prototypes and was going to call it a day. But, just to get a grade for a “Spun Project,” I made an acid etched piece of aluminum and spun it onto the same wooden candy dish mold. Then I made a weird lid that was spun to fit the bottom dish lip. Candy covered or open was the finished project. The whole cl*** loved my acid etched bowl as it was full of candy for the rest of the week. The acid was toxic, sulfuric acid and it made a wonderful rough hewn surface on the smooth aluminum surface. But, watch out for minute splashes on anything... it disappears and hurts on skin. Any type of horsehair brush will do and since it is a small surface, you can watch the acid work. Then when you think it has done its job, wipe it off to stop the etching. So, what happened to my 12 inch spun Moon Disc? It became an 8” Moon Disc because that is what was left of the somewhat concave spinning project and a lathe cut edge. I had two finished miniature moon discs, so later on after college, the two 8 inch discs were mini wall ornaments. They were instrumental in designing two aluminum wheels for a future BMX ***anium wheel design. (sorry to say, those little “Moon” discs were one of those… “if you haven’t used them in a year, out it goes…” a strong hint and command from above. So, out they went to the local dump.)
Worked at an aluminum foundry and when they would do weld repairs if allowed by customer. After welding and grinding welds smooth they would follow with a pneumatic needle scaler to match weld repair to surrounding surface. Needle scalers can be found from $25 to several hundred dollars. For home shop Harbor Freight has: https://www.harborfreight.com/compact-air-needle-scaler-96997.html
I use a needle scaler as well. Quick and looks great! Inexpensive at HF too. I've been having a run on SBC 2x2 conversions, (Sam-O-Rams?), and the welded areas are undetectable.
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