A sandblasting cabinet... Now that's a tool I've been looking for for quite a long time!
One can find different models for sale, but I find them pretty expensive, plus they never have the right dimensions (too large or too small)... So I decided to build my own, with ideal dimensions.
As usual, I started by drawing accurate plans with SketchUp (if you're a frequent visitor on ShamWerks, this shouldn't be a surprise!)...
For the cabinet to work properly, the bottom funnel-shaped sand recycling tank needs to have enough angle for the media to slide down to the bottom. That made my design way taller, and since the cabinet is supposed to stand on my workbench (quite high itself at 95cm from the floor), it's too high for me to use it comfortably. Therefore, I want the funnel to work properly and the cabinet on my workbench, I'll need myself to stand on some sort of support (a rim for example) in order to have a correct working position.
In terms of size, I've adapted the dimensions of my cabinet so that a 15" rim can fit in it. I have an idea for a flexible extension if I need to blast bigger parts, but it'll have to wait..
My SketchUp plan is available for download here.
The cabinet is built out of white melamine 15mm thick chipboard. That's purely an economic choice, as I hate working with this material : but al the boards for €37, that's a bargain... Additionally, the white surface will add a welcomed brightness inside. All boards are glued and screwed on a 27x27mm pine wood frame.
The only difficulty in this process is th bottom funnel shaped part, in which the media is recycled : in order for the assembly to be accurate, I need to make very precise angle cuts with my circular saw... In order to make it easier, I've printed the angle directly from Sketchup (removing the perspective effect to have a parallel projection) on A4 paper (see picture) : then I could directly put my circular saw on the paper and finely adjust the angle by visually aligning the blade with the print. I've honestly been impressed by the accuracy of the method, as my assembly wasn't totally perfect but very close to!
My saw can cut up to a 45° angle ; unfortunately it wasn't enough for one of the angles, so I temporarily glued a strip of wood below the saw's base to reach the 55.7°. The method isn't really secure but it worked like a charm.
As for the lights, 2 spotlights (first price models; €4.95 here) with 60W bulbs.
The blasting gun comes from eBay, a €18.90 model using standard ceramic nozzles. Gloves as well come from eBay ; I could have build'em from scratch using an air chamber and glued rubber gloves, but it was cheap enough to avoid this additional hassle (€19.95).
The acrylic glass piece is cut from a reclaimed piece I had in the garage ; it is mandatory to stick a sacrificial transparent protective sheet in the inside, unless it turns opaque pretty quickly due to the blasting media sanding the glass.
At the end of the funnel is a screw-in PVC plug, epoxy glued. It allows me to drain the media and change it.
On the right side of the cabinet, a PVC 32mm bend allows the connection to the vacuum. A couple of hooks and a rubber band help securing the vacuum hose in place ; an additional rubber band is wrapped around the extremity of the hose, acting as a gasket to make it air tight. On the opposite (left) side of the cabinet, another screw-in plug acts as air intake. It creates a diagonal, bottom-up air flow keeping the airborne particles level low during operation.
Ok, that's a nice box, but it needs to be perfectly air tight as well to work properly. for that matter, all assemblies/joints have been caulked (silicon caulk for bathrooms). Using a metal saw blade tip is perfect to smooth out the caulk with a nice round finish.
The door articulates on 2 shutter hinges (€1.95 each). Airtightness is ensured by a double rubber foam gasket glued around the frame. Hinges are placed taking into account that additional gasket thickness.
Door is closed using 3 screws (with Bakelite knobs I "reclaimed" 20 years ago from the windows of my high-school. I knew that would come up handy someday). It's probably overkill though, 2 could have been enough. Screwing snug tight compresses the rubber foam gasket, that's perfect. I originally wanted to put lever-type metal thingies, but they were too fragile, and do not offer any adjustment levels, so I decided to make my own system...
So, now I have a nice cabinet but it's quite bulky and my garage is small...
Fortunately, I had planned that from the beginning, and reckoned the dimensions of the cabinet accordingly : it's made to fit right above my workbench! With the help of a couple of pulleys, as the beast weighs a good 20kg.
Since I could get my hand on any reclaimed metallic grill inside the cabinet, I just used a piece of plywood instead. Works fine too!
I've ddone my first tests using glass beads (200-300 microns, bought online on Matthys) at 4.5 bars (65 psi), on an aluminium part (the Albatross' intake/exhaust manifold). It was just a 10 mn quick test, without degreasing the part first, which was a mistake since a rubbery/greasy compound on the part prevented me from getting a perfect result. But for a first test, I'm delighted with the result, the aluminium ends up with a smooth satin mat finish, looks just as new!
The cabinet is perfectly airtight, only a few glass beads manage to make it into the glove (as I had to "fold" a part of them to adjust them on the metal rings holding them). Good news!
I just need to remember blowing/brushing away the grit at the bottom of the door before opening it after a blasting session, since it accumulates there ; I'll try adding an inclined/angled piece of wood to fix this later.
Actually, it's almost too airtight : the depression created by the vacuum cleaner make the gloves inflate inside the cabinet, even with the air intake on the door opened. If I close it, the glove become totally inflated and rigid! I'll probably have to add another air intake to limit that effect.
However, just as expected, my 3HP/100L compressor turns out to be a bit small for blasting : it runs a lot, I'll need to take pauses to let it breathe... Or find a bigger one.
The air blow gun inside the cabinet : bad idea, the quick coupler gets jammed with the grit. So either I install a 3 way coupler to have the blow gun permanently fixed to its own hose, or I just pull the hose of the blast gun out of the grit to use it just as an air blower. Well, I'll go with that easier solution!
Here are a few links that inspired me while building my cabinet, for your consideration if you want to do so :
As next I'll try getting heavy rust off of metallic parts using aluminium oxyde grit instead of glass beads. I'll post the results here in that very same article.
I consider as well building a cyclone dust separator (like in the "Dyson" vacuums cleaners) just like this one (in French), this one, or that one here.
To be continued...
Edit 30-08-2012 : a stand for the cabinet :
I've managed to rent the garage right next to mine, therefore I have a bit more of elbow room, so I decided to go for a bit of reorganization. It will be way more practical if the cabinet remains in the second garage, where I'll be able to use it anytime, without having to hoist it down from its storing space (t'was great from the real estate optimization stand point, but not that much when you wanna beadblast a couple of bolts real quick).
In addition, I will keep the cabinet away from the lathe, which wouldn't have liked the abrasive dust that always hangs around the cabinet...
So after some reflexion, and some more Sketchup, I decided to build a stand for the cabinet. Only out of scrap wood that I have laying around the garage. It'll have to be heavy duty since the cabinet is pretty heavy.
The legs will be made out of 62x75mm lumber (the left overs of the workbench project), the rest will the out of 19mm thick melamine chipboard (some od shelves I scrapped). The legs will be chiseled out at the top for the cabinet to slide into them. (check the plan).
I got it right first time... Pretty proud of meself gotta admit.
So now, the cabinet is at the perfect height, no need to stand precariously on something!
The shelf right below allows me to put a bucket to pour the sand/beads into.
Next step, a cyclonic dust separator??
Edit 10-09-2012 : Corundum blasting test :
I've switched the beads for corundum to check if I can actually remove rust. My test piece is an engine support from the Albatross, with quite deep rust, and several layers of paint.
The complete process took me around 10 minutes (at 5 bars of pressure), I you can see the result by yourself, it works perfectly! I'made a short video for you to see how fast it goes.
The only drawback is my compressor : 100L/3HP is a bit low (I knew that before hand), so it tends to run non-stop, with a risk of over-heating. If I ever have to do long blasting sessions, I'll have to make regular pauses for it to cool down a bit.
I also discovered that the corundum media slides way less easily than the beads towardss the bottom of the cabinet ; on the video, you can see I have to push back the sand to the bottom from it to be catched by the intake tube. Well, it's not actually too much of a hassle, and it give a few seconds off to my compressor .
After sandblasting, the metal must be protected asap, unless rust will settle back in a matter of days (even hours depending on the conditions). Here, I use a couple of thick layers of black Hammerite (well, mostly because that's the only thing I had at the garage at that time!).
I'll still have to install a cyclonic separator on the exhaust, and a form of siphon on the intake (as some dust manages to get out that way), and it will be perfect!
Well, I've made the mistake of taking a part off to clean it... Then a second... And a third.... And well, finally, it wasn't a priority for me, but I've restored the whole thing!
I must admit, spending time of the online (french) forum usinages.com (there's a thread about my lathe there), and seeing all these beautifully restored machines, temptation was to high!
I've started by painting the stand. Degreasing using solvent F (naphtha) and Scotch-Brite scrubbing sponge to remove most of the thick coat of grease that was all over it (with some additional WD40 on sticky grease patches). Then complete washing/cleaning using "St. Marc" (french equivalent of your "Cillit Bang", I guess), rince, and a good rub with 90° alcohol to remove any remaining greasy film (the cloth has to remain white when doing this).
Finally, a coat of green, hammered finish Hammerite paint (not that easy to brush, but final visual result is really nice).
Painting the bed and the headstock : same process as for the stand, solvent F/Saint Marc/90° alcohol/Hammerite... While cleaning'em, a lot of metal chips came out of the little space between the bed and the headstock : aluminum, steel, brass, bronze, nylon, you name it ; my little lathe has been using on many different materials!
On some of the following pictures, you can see the bed standing up in quite an unstable position : that was the only way I could access the under and inside parts of it. Unfortunately it almost fell off on me, my cervical vertebras hurt for 3 days... Don't do this at home, kids.
Then I start on the feed gearbox.
There again, I originally just wanted to give it a good external clean, but... I got carried away.
I must say I had a moment of doubt when everything was disassembled on my workbench, with gears averywhere... But finally, with a bit of patience, methodology and organisation, it's not that complex.
Some of you may think I went too far with the mirror finish on the bronze bearings, but I couldn't help.
Then, dismantling the carriage assembly, down to the smallest screw... Now this is where you gotta be cautious : dozens and dozens of small parts just waiting to be lost... You must be organised : containers, reclaimed jam jars, Ziploc bags, hand-drawn schemas, pictures, anything's good to make sure you don't lose anything, and preparing for the re-assembling step later.
I won't go through the detail of cleaning each and every part here, the process was always the same : degreasing in a tay with solvent F (naphtha) and a brush, then brushing/polishing with a rotary brush mounted on my hand drill (soft blue plastic brush) to remove oxydization marks. Eventually, some scrapping when there was paint stains, and/or 600 grit sandpaper with abit of WD40 to remove deeper oxydization.
Aaaaand finally, reassembling everything with clean oil/grease, while adjusting all the necessary plays : this is the funny part.
Tailstock and spindle
There's stillthe tailstock and spindle to restore. Regarding the latest, you must be extra cautious to reassemble it just the way it was originally, since the different parts broke in together.
Originally, my lathe had a little drawer, which is quite handy to keep tools protected and within a hand's reach. Unfortunately, the drawer was lost at some point in the history of the lathe. So, here I go, building a new one out of 10mm. plywood.
A quick tip about plywood : to have a smooth finish once painted, you have to sand it before painting ; a good thing is then to humidify the wood a few minutes before sanding (use a spray or a sponge to slightly humidify the wood, don't soak it!). This will raise the grain of the wood, so you can sand it smooth. If you don't, the grain will raise with the humidity of your paint coat, and you and up with an ugly rough surface.
Since I don't have three-phase current available in my workshop, I use a variable speed drive to drive the motor (I use a Schneider Altivar 31, great product.).
The original motor (1,5 kW/2hp, dual speed) will finally be in too bad a shape to be used. I don't know what its previous owners did with it, but boy does it have suffered : the output shaft was beaten, it was impossible to mount the pulley on it without heavy vibrations. I may have been able to grind it back straight, but since the motor made a naughty noise when running, I preferred to replace the motor + pulley assembly. For 160€ for both (same power as the original motor : 1,5kW, 1500 rpm, pulley 160mm in diameter), I preferred to have my mind at peace on this point.
As per the commands panel, I had on my mind for quite a long time a nice engine-turned aluminum panel. But I wanted the engine turning pattern to be very regular, so I built myself a jig for that.
The abrasive grindstone I use is from PolirMalin, a bit expensive, but does a great job. The circles are 30mm in diameter, I've decided to shift each line by half a radius, the final aspect is much nicer. A bit more complex to do, but the result is worth it, see schema below. This is when the jig comes really handy!
403 holes precisely drilled (that took a while...) in a bit of melamine chipboard (not ideal, but does the trick).
The holes on each line are spaced by a radius distance (15mm). On each line, the holes are shifted by half a radius compared to the previous one.
Then I just need to put the buttons in : I use paint adhesive tape (two layers) to protect the aluminum while driling the holes. Additionally, you can write on it, which is hande to note down where the holes should be!
As per the electrical box, I called for some help. I didn't have all the necessary skills/knowledge to make one up to standards, plus the equipment get pricey when bought one after the other...
Fortunately, a member of the forum usinages.com proposes refurbished high-end second-hand products (thank you so much Emmanuel aka "Turbo Gros Michel S.A" for your help!), and he prepare a complete electrical box for me : relays for the motor drive, pump and light (even I don't use these last two for now), 27V transformer for the commands, 12V transformer for an electronic speed indicator that I'm gonna install later, emergency stop button with an adjustable 2.5s temporizer for the speed drive (which wouldn't appreciate being disconnected while in charge, so it waits for the motor to brake before shutting the current input)... A real electrical bow, up to standards, full options!
And finally, the result... It's such a pleasure to use this machine!
Here are a couple of "before-after" pictures!
Motor pulley :
Speed drive :
Electrical box :
Miscellaneous (paint, hardware...) :
The final total cost is way below the current price this kind lathe resales nowadays, so I guess I did good... Well, obviously, as long as I don't take into account the dozens of hours of labour I've put in it!
My only regret : the size of this lathe. A bit too small, I can't work on my VW drum brakes for example. But well, a bigger lathe wouldn't fit in my workshot anyway, would it??
That's it for today fols, I'm going back to the workshop, I got metal ships to make!
"Small" upgrade of my workshop...
First, I managed to get myself a second garage, next to the first one. Well, not exactly next to, so I can't just remove the wall between'em, but close enough. Not a perfect situation, but better than nothing.
Next, I had an opportunity for bargain priced floor tiles (thanks a lot to my buddy Dangerous for this, and lending me his Type 2 to transport everything!), so here we go : let's tile them garages!
So, I have two garages, 17m² (183ft²) a piece, so a total of 34m² (366 ft²) ; I got myself 40m² (430ft²) worth of tiles, just to have some room to deal with cuts and broken ones.
These tiles are 50x50cm (20"x20"), solid porcelain stoneware, 9.5mm thick, anti-slip texture : 27 packs of them, 27.7kg each, so almost 750kg to move... Meh, I'll just get my spine replaced after this one.
Note : for you to imagine the 30km trip with the Bay Window Type 2, packed with 750kg of tiles, in winter, under heavy rain (orange weather forecast flood alert), without any heating (so windows wide open to get rid on the condensation, so in rained an much inside as it did outside!), with a fire extinguisher at my feet "jus in case because I have a leaky fuel pipe", and the obviously vintage braking system, I suggest you watch again the classic movie "The Wages of Fear" (1953).
Why tiles in a garage?
To answer shortly : way easier to clean, a quick sweep and it's clean.
I was rather happy about my floor paint, after 3 years of use : it resisted quite well, only a couple of compounds manage to dissolve the paint if let too long in contact (mainly braking fluid and aceton).
But my floor isn't perfectly flat : the concrete slab had originally been indented with a spiked roller to make it non-slip, and even though I had used a concrete grinder to smooth the surface (see this article), it's still full of small holes that keep gather dirt. Impossible to keep it actually clean.
And for those of you who think : "yeah, but if you drop a tool, your tiles gonna break!" : well, I know a tiled car body shop, they have tools falling everyday, and they even hammer form sheet metal on the floor tiles! So, no, I'm not too concerned about solidity!
And if I happened to break a tile, I have quite a few in advance, I'll just replace it with a new one...
OK, here we go!
First step : empty the whole garage to be able to tile : in itself, it's already a heavy project, fitting in one garage what usually fits in two... It's like playing a life-size Tetris.
Next, carefully preparing the floor : sweeping, vacuum, complete washing/rincing using "St. Marc" washing soda, and a coat of primer to make sure the tile adhesive sticks to the substrate. Then, tiling using "Parexlanko" tile adhesive (spread with a 9mm toothed applicator, using the double-gluing technique on the back of the tiles, important for solidity), and water-repellent sealing comound from the same brand. Nice products, I would use th same with no hesitation ; a total of almost 3 bags of 25kg of adhesive per garage were used, so it's another 150kg to transport... Plus 25kg of sealing compound for both garages...
As expected, the walls aren't straight, so I tile everything perpendicular to the garage entrance (if you ever so such a job, take your sweet time at the beginning to make sure you start square, Pythagoras is your friend here!). A world of thanks to my buddy Flo here for lending a hand!
I finish it up ith a stripe of grey paint at the bottom of the wall, to keep it clean when I sweep the floor (and cover the stains made by the sealing compound). Another solution would have been to make "skirting boards" out of the remaining tiles, but the added thickness would have been in the way when I install my shelves.
So, first garage done ; this one will be mainly used for storage, so I install there all my shelves. And since I scored on LeBonCoin (the french equivalent of Craig's List - that was a steal!) a set of really sturdy boxes that neatly fit in the shelves, I'll finally be able to sort out my mess stock!!
One down, one to go. Heads up, we're only half way!...
This one begins with moving the 350kg of my lathe (which almost fell on me this time, thanks Xavier for your help!).
Next is exactly the same procedure as for the first garage, deep cleaning and priming the floor (primer is mandatory to install tiles on a painted floor), and finally tiling :
And two down! Done! PHEW! I had under estimated the amount for work tiling such a surface would be!
These small things that make your life easier...
In the first garage, I first install 4 two-by-threes below the glass roof I have at the back of the garage : that will be a tire rack, and that much room saved!
Build in 3 minutes with what was laying around : 2 angle brackets, 3 old roller ball bearings, a threaded rod and a handful of bolts... And here you go, a nice kitchen roll holder running on ball-bearings!
Here's something I should have done 20 years ago, I keep using it all day long!!
Now for the workbench : I paint the feet/supports to be able to clean them later, as the raw wood stains very quickly in a workshop environment (and for the looks, let's be honest!). I give it two coats of a nice vintage "Eucalyptus" green, with a light sanding between coats. Sanding is mandatory on wood, as the fibers tend to raise after the first coat.
The shade of green is shamelessly copied from inspired by Jack Olsen's garage, of which I'm very fond of... If you don't already know it, you must give it a look on 12-GaugeGarage.com, and check the build details on GarageJournal.com (be careful with this forum, it's addicting and you quickly end up spending hours there!)
Workbench again, that was a paint in the ass to make : a strip fitting nicely in between the workbench top and the rock stone wall behind. No more washers or nuts rolling all the way behind the bench! Looks like nothing, but the usage comfort is so much better now! On the down side, it took me almost half a day fitting that strip, using a rasp and a Dremel...
The strip is made of 10mm thick MDF, covered with the edgebanding material that came with the bench top. It's then screwed on top of a 1"x1", itself glued/screwed to the back of the bench top. Neat!
I found on LeBonCoin again (40€, a bargain!) a nice all steel tool cart... Probably originally a medical cart, with that stainless top...
A bit of elbow grease and some paint to match the workbench, and it's perfect!
There, that's it, end of this upgrade, with a sore back and knees (all my respect to the guys whose job is tiling!)... Just to compare, here is how it looked like before...
OK, enough, now that it's nice and clean, let's put some grease and rust all over it!
Back to cruising speed and altitude at the workshop... Over'n'out!
Poorly cast iron, with many casting defects filled with bondo, with a nice paint to cover the crime... As you can guess, all of this is going away the first time you use a blowtorch or a hammer.
The "mechanical" part is no better, the screw is made of lower-grade steel (the kind of steel used to shoe rabbits, as we say in french), the nut is tiny, secured only with a 4mm screw that broke on first use...
Pictures are worth a thousand words they say, here's what the beast looks like after only 3 years of occasional, osft & gentle usage. I does not even work anymore, the threading in the nut is mostly gone, one as to apply quite a lot of torque to actually tighten the vise, and if you tight it a too manly, the threads just "skip".. Pure bliss.
But this was BEFORE.
Found on LeBonCoin (our french equivalent of Craigslist), for merely the same price I paid for the shity chinese thing, a beautifully restored "Sambre et Meuse"!
For those of you who don't know about that brand, Sambre et Meuse is a steelworks company, founded in the early 40's, that produced this kind of tools until 2009 (when they sold that branch of their activity to Dolex). The company still exists today, their main activity being large steel castings for train industry.
These vises are well known upon machinists for being sor of the "Rolls" of them all, dating back from an era when we had a flourishing industry in France, producing high quality stuff...
My new vise ain't perfect, with a few saw marks on the jaws, but it's very clean for a tool that's probably around 40 years old. It's completely made out of steel (all 14kg of it), and turns with the slightest push of a finger!
Its previous owner lives more than 2 hours drving from my place, so thank you Thierry for picking it up for me while I was arranging logistics!
Anyway, my point is : if on a garage sale you were ever to find a "Sambre et Meuse", make sure you don't miss that oportunity ; they don't make'em like that anymore!
It's been 4 years since I've gotten my lathe, so as one can expect, I've been wanting a milling machine for quite a while now... (and the hours spent on the usinages.com forum have not helped)
But the thing is, in my area, these kind of machines are scarce ; unlinke in northern or eastern France, areas that have and actual industrial past, and where you can find second-hand machine adds regularly.
But the main problem remain the sheer size of my workshop : it's really small (that's what she said), therefore I need a small milling machine if I ever want to fit it in... Ideally a Deckel FP1 (beautiful but so expensive I'll never be able to afford it), or a small Graffenstaden, a WGM... Or if I accept to go with shorter travels, a Schaublin (overpriced), a Crouzet...
Anywho, I kept an eye on adds in the area (because when it comes to transporting 500kg of cast iron, it better not be too far!), without putting too much hope in it...
Untill last July when one of my alerts popped up : years of patience finally paid as this appeared on LeBonCoin (our CraigsList) :
A cute little Crouzet-Valence FC100, (same band as my lathe), just 30 minutes away from my place!
If you're curious, here's the documentation.
I first quickly check in Sketchup that it will actually fit in my workshop, and I gave a ring to the seller, who told me he already had several calls (he was actually surprised) : first come, first served! So I jumped into my car and went to see the beast in oder to lock the sale!
Negative points :
Limited travels : X 220mm / Y 100mm / Z 330mm. That seriously limits what I'll be able to do with it. Still good to learn, and enough to work on cylinder heads!
It's missing the X/Y handwheels, and Z one has its handle broken. Shouldn't be too difficult to find new ones.
Rare W20 attachment, won't be easy no find tooling.
No automatic feed (not because it's been remove, as it's frequently the case, but because the machine was ordered specifically like that), but I don't really care since I have something in the back of my mind.
Positive points :
The FC100 is a good machine, rigid and heavy.
It's in a pretty good state, with almost no play : it quite obviously has not worked a lot. I've been told it was originally bought by the Aérospatiale (they have an important complex not far from here), and has only ever been used for smell jobs.
It has the universal tilting head.
As much as the W20 attachment is not ideal, at least it's the same as on my lathe, therefore I already have a few collets to fit in!
But mainly : the asked price! For 300€, there was no way I'd miss it!
Long story short, I transport it back to the workshop on July 29th : I had to transport the machine laying on its back, as my garage entrance isn't high enough to do otherwise... Not perfect, but I had no other choice. And it looks like the rental Citroën Berlingo was made specifically for that machine, as it perfectly fits in!
Loading the machine in the truck was just a 5 minutes job at the seller's place thanks to his forklift... But unloading it was a whole other story! Even with a borrowed workshop crane from a nearby mechanics, it was 2 hours of heavy lifting! Many thanks for lending me the crane, and a 1000 thank yous to Xav'Yeah, my partner in crime whom I manage to involve it these hassles! Ain't moving 450kg of cast iron in an overheated 1 car garage a fun task?
The machine will end up spending the next 3 months on its back, until I manage to get my own crane (I had a lot of delivery problems with this one) and free up some time to deal with it. So finally, November 8th, the machine is finally standing up! More heavy lifting, done on my own this time, but it's finally resting where it belongs!
Now I need to find some spare time to take care of that old lady. I don't plan on doing a complete restoration, as it's in a relatively good shape already, a good clean up should be enough (well, it'd look great in the same green color as the lathe, though...). And why not a few step motors to pilot the whole thing...