Hello Ford man
Me and the guys still blast and it is a good procedure to metal finish a lot of parts we feel.
At Ford racing, and Holman Moody, then Stroppe, we glass beaded hundreds of intakes in a cabinet we only used for aluminum,had a way to clean them well, then fitted them back on race engines only, and won a lot. Never had these issues some people describe so there must be something that changed, or, the blaster created the disaster. Sorry
At our big current shop, we have 3 bead blasters with fine and finer media, and we use one for scabby or rough steel, one for only very clean steel before we heli arc it, and one for only pre cleaned aluminum. No dirty parts go in the blasters to keep the media nice.
If you are worried maybe do what we did and don't get too stressed.
On an intake, just plug the tapped bung holes,,,LOL, for the senders for example, with any plug, finger tight, and we have these bolt on plates too. Or,just use duct tape for the gasket area, remove any shields from below the intake obviously, adjust the pressure low, and mist it on. Go even and make passes like you are painting the part, and turn down the pressure to just enough to make it pretty.
Our trick was not to blast media inside hard to clean passages.....no reason to blast inside the water jackets for example,,,? So tape them off to make cleaning it before assembly a lot easier.
Now on other media, we did walnuts shells and dipped and soft blasted dozens and dozens of Street Rod projects for a top professional Rod shop in the 80s and 90s, and in this new place. They all have a nice place, but...
All methods seem to have some issue that you simply avoid or work around.
We did magazine cars for various publications, and on a few magazine cars for Hot Rod, they wanted the cars blasted with walnut shells to do a side article on how to strip a big door car. These were for Project 57 and another years back.
It is true, the walnut or other organic shells do no deform or bend the sheet metal, that's great, but the shells can get stuck in many seams and folds and crevices too. So you get the body back, looks nice, all filler is gone, rust is gone, but this process also has issues.
When you begin to prime and block, and prime and block the car, about 50 times,,,ha ha,,the darn shells can show up in the paint despite meticulous pre cleaning. Just like the beads, they can get stuck or rest in hidden places, so? You can also tape some hard to clean places off, and have less issues later
We have dipped many many bodies too. That is nice, leaves a coating on, however, if the body is not thoroughly rinsed and rinsed, and neutralized,,,,,the acid can hide in the cracks and crevices, and continue a new rust even or cycle. You can carefully scuff the car, prime it, set it on a jig, and weeks later, residueal acids can cause a paint event or flaw,
So they clean them a lot better now, but you have to be careful. We RECLEAN them after dipping and let them dry for weeks, then base prime them, and wait as the metal work gets done
Do we still use all 3 above? Sure do. And the big or solid shops we visit or use around here still have a blast cabinet that gets used a lot. Your technique is important I think.
I like the finish look on a bead blasted intake. It makes several of us recall how the FORD sponsored race engines we did and did, looked before a race. After a few races, the stains can get baked in bad, so mask or block the coolant passages, blast her after pre cleaning, then blast her light in CLEAN media, that is key.
Then we dipped them in our reactive pre cleaner tank, they were agitated, then pressure washed, blown out well,,,,then usually we would, and still do, set the intake in the bottom of a solvent tank over night, blow it off well again, and run it
It is true, if a guy doing heads, is not careful, and blasts a used head for 30 minutes, and just stuffs the coolant passages with glass beads, you can clean them a lot, but see beads continue to fall out on the finished work. This is also avoidable by just masking or blocking off the coolant paths again. On an FE head, 4 little strips of Duct Tape keep the beads where you want them, maybe 5, depending. But for an iron head, I still just Hot Tank them old school, then into a block cleaning pressure washer. Some I dip in Acid to remove rust, I blast a lot still too with a pressure washer, then soap, then oil
I wonder how the beads destroyed a guys build? Must have been the metal media and little to no cleaning after?
We raced a lot of bead blasted heads too, but blasted the chambers and ports, and had spark plugs in, and the above passages closed
Not trying to contradict anybody, but a lot of people blast intakes to get them shiny and bright again,,,,,or, we cold tank them like a VW crank case if you have a place
Tape off the coolant through the intake gasket surface, and I don't blast the machined surface there. plug the pipe bungs, tape off the thermostat housing flange, we bolted a dummy on that was plugged, tape off the bypass nipple, tape the carb flange closed if you like, we did not quite often, and then hit it even and light with a blaster if you want it bright again
Some guys do tape off the entire carb flange, and the entire gasket flange....., then just don't blast at the tape. I do it that way and so do others, much less fuss
Blasting is like just about any trade technique probably, there are tricks, and the more you do it, the better you get
Good luck
If you have a open blast place, do a test, some blast cabinets can be very dirty. THEN, they darken the part due to grease,carbon or paint in the media
Do a test maybe. You know the media is fresh if the basically clean aluminum part gets a lot brighter. If it gets dark, have the guys dump a new bag of media in it. That is cheap
Have fun....
Have fun !
I just had to comment, we won a lot of Championships and races for FORD with bead blasted intakes and it was actually considered 'trick' then....Must be getting old
