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Clean metal finishes for optical assemblies I need some suggestions for finishes for aluminum and steel that are clean. What I mean is no oil film, no rust, and clean to the touch. Something I can scrub with hot water and dish detergent, let dry, and handle with grubby fingers, and not get any sort of corrosion or staining. Environment is a normal office. I really like passivated stainless and anodized aluminum. I don't like anodizing changing dimensions on my holes. What other finishes should I look at. How does alodine feel to the touch, is it pretty clean? Is there anything I can put on 12L14 or mild steel to make it nice to handle, without the thickness of powder coat or paint? I have some black oxide 18-8 stainless screws that feel nice. Does anyone know what coating this is? I don't know a lot about metal finishing, so I'm mostly looking for ideas.
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Jun 6, 2021 09:46
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Thanks! Protectaclear seems like a useful thing to have around the office. I guess I should mention that I'm not a machinist or a metal finisher, I just need some parts made. My next step is to talk to a machinist about my part and finishing options. I sort of expect the machinist will then farm out the finishing to another shop they know if it's plating or anodizing, etc. I'm pretty new to designing/buying machined parts. I have another part coming up that will have about 50 threaded holes (1/4-20 and M5) in an aluminum 12x24x0.25" plate. I really want a black type 2 anodize, but I also want nice threads. The order will be for 3-5 plates. How is this usually handled? A second pass with taps, or masking the threaded holes? What about precision plain holes for dowel pins and similar? (I hope these kind of questions are welcome here. I'm trying to not design stupid parts.)
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Jun 6, 2021 19:35
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If I'm getting a small batch of parts anodized (like 5 small parts each under 10 sq in), and I want a color other than black, how is that done? Is it something easy where my couple parts get dunked in a separate bucket of dye, or does it involve a big setup and lots of cost? Instead of some pantone number or whatever, can my spec be "any bright/bold color red, orange, green, blue" and then hitch a ride on a larger anodizing run? Does this make my tiny orders less of a hassle/cheaper, or does it just confuse the process because I'm not being precise about what I want? This is for internal parts/tooling where the color doesn't matter and I think a bright color would look nice or be easier to find on my bench, etc.
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Jun 6, 2021 22:27
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Hi! I sanded some aluminum, cleaned it, and put on 2 coats of protectaclear. There are some strange spots that were visible before the protectaclear, but are now more visible. Whatever it is, it is impervious to Dawn, acetone, and sandpaper. Maybe it's harder regions of metal? Mostly I'm just curious. I'm not going to refinish this piece. It's 3/8 x 6" extruded 6061 T6511 (Sorry I didn't take any pictures before it was coated. It didn't look as prominent then, so while I noticed it, I didn't really care.)
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Jul 20, 2021 03:15
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Hello, metalworking goons. I took a 2 day MIG welding course at a local industrial arts center, and now I am going to buy a mig/stick machine (probably ESAB 215ic). I will be welding mild steel 1/8" - 1/4" thick, including skid plates for my offroad vehicle and similar. I might need to weld some thicker plate for my welding table. But I have a couple questions. Is there much difference in identical spec consumables? For example, is all 0.030 ER70S-6 the same, or are there differences in behavior/use between brands? I imagine lovely ER70S-6 wire exists, what aspects are lovely? Is flux core better than solid MIG wire wrt cleaning of contamination? I get that the flux protects from the atmosphere, but does it also eat oxides and crap like a 6010 electrode? What MIG wire/process is good for dirtier metal? I want to put down some beads of hardfacing in two spots where my skid plates see a lot of wear (build a little lip ahead of a bolt head to protect it). The base metal is 3/16" A36. This plan is admittedly 50% for lols, but I see I can get 0.035 55FC-O in 1 lb spools, so maybe I should try it? How does the wire behave when welding vs ER70S-6? Is it easy, or a huge pain in the rear end?
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Mar 3, 2022 00:19
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No, these details are very useful, especially manufacturer's brand names like Fabshield 21B. It makes it much easier to search for more info. Thanks!
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Mar 3, 2022 09:59
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Wesleywillis, what stick electrodes do you use at work for hardfacing, and on what kind of equipment? I can run stick in my machine. (I'm mostly just curious) e: my new welding space  is about 2 blocks away from a steel seller and a professional welding shop. Once I get my machine, I need to go over there and try to make friends.
ryanrs fucked around with this message at 05:20 on Mar 4, 2022 |
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Mar 4, 2022 04:37
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OK, I dunno how many times you've been stabbed / stabbed someone. But if you stab a split ring with a knife, the ring will just get bigger until the knife fits.
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Mar 5, 2022 01:14
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Welding Tools (besides the welder) What welding tools are useful to have? I'm thinking things like those deep throat visegrips, the ubiquitous mig pliers, magnets, etc. I see a million styles of clamps, what should I get to go with babby's first welder? Assume my welding table is just a flat piece of steel, without any fancy slots or holes. Or should I have slots and holes? If something like a fabblock is genuinely great to have, even for rough jobs, tell me now. I already have an angle grinder and a dozen different kinds of discs, so I think I have that covered. And a carbide cold saw and a bench grinder.
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Mar 5, 2022 06:28
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Mar 8, 2022 10:42
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I'm going to hit up some Bay Area steel suppliers on Monday, probably Alan Steel & Supply in Redwood City, and Maxx Metals in San Carlos. I've never been steel shopping before, so any tips are appreciated. I have a few shapes I definitely need, but I also need a certain amount of misc stock just to have on hand: flat strip, angle, square tube, etc. It's kind of hard to plan this trip, because nobody lists prices (I guess it fluctuates a lot with steel prices). So I think I'll go in with a list of prices from Grainger, as an upper bound / sanity check. I hope I don't need to buy 20 ft lengths of everything. Maybe they will have lots of shorts I can get for cheap? Or maybe every other hobby welder in the Bay Area has already done that. e: Just found this: Onlinemetals.com protobox assortment. This is perfect for building up my metal inventory. e2: Online metals has cheap shipping only on bar and round stock, not on protobox assortments, so that instantly triples the price. ryanrs fucked around with this message at 00:33 on Mar 21, 2022 |
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Mar 20, 2022 23:38
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San Jose is next door! I will add Metal Supermarket to my list. e: I should also mention that I can get Grainger products with no shipping (will call). ryanrs fucked around with this message at 02:45 on Mar 21, 2022 |
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Mar 21, 2022 02:06
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Oh god, don't say that! That's what I'm afraid of! Maybe steel is just pretty expensive?
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Mar 21, 2022 04:24
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How big of a 'foot' do I need to safely hold a 80cf inert gas cylinder? I want it free-standing, like a Christmas tree stand. A The other possibility is to bolt a cylinder bracket to the wall, but I am trying to avoid that because of reasons. e: wait, welding carts have about a 18" wheel base, so I need an 18" circle. Less, really, since my bottle isn't raised up on casters. ryanrs fucked around with this message at 04:35 on Mar 22, 2022 |
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Mar 22, 2022 04:20
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Hmm, on second thought, maybe the tank stays by the wall near the outlet, since argon hose extensions are cheap. I don't have a cart for my welder, and no immediate plans to make one. But it has a handle and I can just pick it up and move it. P.S. Any tips for welding 2x2x0.120 square tubing to a giant piece of 1/2" plate? It's a horizontal fillet weld, thick section on the bottom (legs for my welding table). I'm guessing I'll set the machine for 1/4", and aim mostly on the plate, just quickly kissing the tube. I'll weld some practice legs in the middle of the table, then grind them off.
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Mar 22, 2022 05:26
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I just realized that if I ever want to take the welding table out of the room it's being built in, I'll need to cut the top off. So I think I'm going to just tack the legs to the table. Well, not tacks, but something like 4x 1/2" welds on the corners of each 2" square tube leg. Then I can remove the welds fairly easily with an angle grinder when the time comes. I don't think joint strength will be an issue at all, but I look forward to doing destructive testing to verify.
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Mar 22, 2022 23:12
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Tabs to give my grounding clamp something to bite: I want to make it copper for that extra bling, but I'm not going to buy a tank of 100% argon just so I can mig this with silicon bronze. In theory, my friend has an acetylene torch somewhere, but that too sounds like too much hassle for a gimmick. Copper-clad steel would be nice, but sendcutsend.com doesn't stock that. What happens if I weld 304 stainless with ER70S-6? Does that work ok? I don't care if the filler metal rusts. ZincBoy posted:This is an ideal stick job though and that is how I would do it. A couple passes of 1/8" 7018 rod would be plenty good and not really any slower than MIG. My welding machine can do stick. I only have a couple hours of experience with stick, though. I welded 1/8" coupons with 6013 and it worked ok. ryanrs fucked around with this message at 07:30 on Mar 23, 2022 |
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Mar 23, 2022 06:21
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The shop has an exhaust fan in the roof and I wear a P100 respirator. GMAW is pretty clean. e: I ordered some unbelievably cheap $9 casters from ebay. It's a large 5" caster, bigger than a shopping cart wheel. I rate them as pretty decent casters, i.e. extremely good for $9. I haven't mounted them to anything yet, but they have real bearings and good wheel locks (that lock both the wheel and swivel with little/no play). ryanrs fucked around with this message at 18:55 on Mar 23, 2022 |
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Mar 23, 2022 18:28
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Serious question: what is going on here? Is this how you're supposed to do vertical mig welds? Or does this youtube person with thousands of subscribers and a bunch of welding videos...not know how to weld? https://www.youtube.com/watch?v=vW37PHs5O0Q&t=225s
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Mar 25, 2022 02:42
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honda whisperer posted:That guy does not know how to weld. Ha ha, that's amazing.
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Mar 25, 2022 02:49
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Gas Cylinder Stand and/or Double-Barreled Umbrella Holder   Steel ring 8" OD, made of 1 x 0.25 hot rolled steel. Gusset plates laser cut 0.119" cold rolled steel. Post is 1.5 x 0.120 square tube. Base plate is 12 x 12 x 3/16 Wall arm is 2.5 x 3/16, screws into a stud (no drywall present) I wanted a sleek design without a lot of bracing and diagonals. But it also needs to be strong enough to survive bumps when dropping in a cylinder. I think this design will be strong enough as shown, but it can be strengthened further by welding side plates to tie the exposed gusset edges together. The gusset plates were cheap to have made, less than $4/ea, albeit with a $29 minimum order. Note that I'm using this design with small 80cf cylinders, which aren't very heavy. e: weight is 25 lbs ryanrs fucked around with this message at 08:13 on Mar 25, 2022 |
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Mar 25, 2022 08:03
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Did a couple test welds today! 1.5 x 0.120 sq tube to huge 1/2" plate     Bent it all the way down, bent it back up, and it broke when I tried to bend it down again. Base metal fracture in the HAZ at the edge of the bead. 1 x 1/8" angle to 1.5 x 0.120 sq tube     This was much more difficult to bend. I used a cheater bar + stomping to bend the angle over. Then I used a sledgehammer to straighten it back up and bend it over the other way, which is when it fractured. It took a half-dozen blows with a 10 pound sledge to break the metal. As in the first weld, the fracture was in the base metal at the edge of the weld bead. Based on these results, I believe these two welds were sound. But my intro to welding class didn't cover weld testing at all, so if I'm wrong about this, please explain. (I'm extrapolating from what I know about adhesive testing.) e: re. Destructive Testing https://www.youtube.com/watch?v=IHcjRj2A_w8&t=132s ryanrs fucked around with this message at 05:57 on Mar 26, 2022 |
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Mar 26, 2022 05:05
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honda whisperer posted:A CO2 fire extinguisher Ahahaha, the 10 lb CO2 fire extinguisher arrived and it is goddamn huge. It's a great big bastard that could double as a battering ram.
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Mar 27, 2022 17:34
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So how do I use acetone in the welding shop? I guess I need a metal trash can with a lid?
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Mar 28, 2022 23:24
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I hate that this shop space has wooden floors. (but I like the 24 hour access, 240V power, and $0 rent)
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Mar 28, 2022 23:44
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It's not gonna last, heh. I'm just squatting here until a paying tenant shows up. e: bought a $100 UL listed oily waste trash can. Considering the deal I'm getting on rent, not burning down the place is really the least I can do. And it's good if the landlord thinks I'm a huge fire safety pedant. ryanrs fucked around with this message at 05:55 on Mar 30, 2022 |
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Mar 29, 2022 00:08
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Welding table finished!  
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Apr 3, 2022 02:01
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honda whisperer posted:Very nice. I like the ground tab. I have a bunch of extras because of the minimum order. PM me your address if you want a couple. They are 2x3x0.135" cold rolled mild steel. e: offer is for anyone in the thread. I will prob ask you to paypal postage, though. 
ryanrs fucked around with this message at 03:31 on Apr 3, 2022 |
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Apr 3, 2022 03:07
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The big gains are when you trade off thinner wall thickness for larger diameter (so total amount of metal is constant). Thinner walls make your tube less strong and less stiff, but the larger diameter increases stiffness by A LOT, so overall the thin wall, large diameter tube is stiffest. For torsional stiffness, I think stiffness is proportional to radius^4. This means a 20% increase in tube diameter gives double the stiffness. ryanrs fucked around with this message at 21:55 on Apr 7, 2022 |
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Apr 7, 2022 04:11
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What's the proper MIG welding technique to use when your fit up is lovely and there's a 1/8" gap? (I'm learning fabrication via trial and error.)
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Apr 11, 2022 03:40
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thanks!
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Apr 11, 2022 04:15
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I want to do some small MIG welds on 1/4" passivated 18-8 fasteners (cheap stainless bolt). Basically welding a nut to a bolt as an anti-theft measure. Can I just load some 308LSi 0.030" wire and run it with my existing cylinder of 75/25 argon/co2? I'm really hoping the answer is YES, because I do not want to buy a tank of helium or w/e just to make a couple tack welds. Do I need to do extra-effort cleaning to remove the passivation layer, or can I just mow through it? Maybe the extra silicon will help clean it a bit? For context, if welding stainless is significantly more complicated than this, I'm just going to tack it with ER70S-6 and paint it with cold galv. Like, I'm not going to TIG it.
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Apr 24, 2022 06:53
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Excellent, that's what I wanted to hear! (I have a blue sharpie for color)
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Apr 24, 2022 07:52
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The widely accepted mechanical engineering authority, the McMaster-Carr Catalog says:quote:Use dowel pins as pivots, hinges, shafts, jigs, and fixtures to locate or hold parts. For a tight fit, your hole should be equal to or slightly smaller than the diameter shown. Breaking strength is measured as double shear, which is the force required to break a pin into three pieces.
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May 26, 2022 21:27
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  I have a skid plate on my minivan that has been almost strong enough for my abuse. I want to add some ribs, but before I can do that, I want the skid plate fairly flat. That has proven to be quite hard! So instead, I'm thinking of having the fab shop cut me a new one from the original CAD files. Then I will do the welding myself, including some strengthening and ribs. The skid plate is 35x39, 3/16" A36. Of course, should I go down that route, maybe I should have the skid plate cut from better steel. What alloys are available with a 50+ ksi yield point, as delivered? Easy mig welding is a must, with no pre- or post-weld heating (or at least very simple procedures). I'm not especially interested in getting the finished skid plate heat treated. Must be available in 3/16" thickness or very close to it. Maybe A588, 4130, A572, or A514? I can't even find pricing info on most of these. Chromoly or HSLA? Will welding it be straightforward for me, a relatively unskilled hobbyist? Is this all a bad idea and I should stick to A36, just more of it?
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May 27, 2022 01:46
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 2000 FWD Toyota Sienna minivan. It has a thread in AI. I need the skid plates because the van sees a certain amount of abuse on the trail. https://vimeo.com/667553564
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May 27, 2022 02:55
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Last time I thought about this, I think I came to the conclusion that if I wanted to use fancy alloys, 7075 aluminum is stronger and lighter than any of the steels, so I shouldn't even think about high tensile steel. Either learn to weld aluminum (no), or make it out of A36 and make up for the material weaknesses with better design and fabrication.
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May 27, 2022 03:13
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Yeah, and a big motivation for this project is "learning to fabricate 4x4-type stuff", so messing around with fancy alloys is probably getting too far into the weeds.
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May 27, 2022 19:26
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Tell me about this metal: McMaster: Ultra-Strength Carbon Steel 100ksi yield, low carbon, HSLA, I think it's hot rolled, not quenched and tempered. Says it's easy to bend and weld. Gee, that all sounds pretty great! McMaster says it's similar to Tata Ympress 100 XF (pdf). I've been building stuff for my car out of 3/16" A36, and it is almost strong enough. This high tensile 4mm plate should be much stronger and a bit lighter. I know a shop with a 130T press brake for forming. What are the downsides (beyond price and availability)?
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Oct 18, 2022 06:19
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| # ¿ May 3, 2024 01:54 |
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My hobby welding machine can only fit 8-inch, 11# spools, but all the exotic wire only comes in 33# spools. Do people respool wire, or what? e: ER70S-6 vs ER80S-D2, in an extremely unscientific test using a sledge hammer https://www.youtube.com/watch?v=h1EqpIy5Igk Result: ER80S-D2 produced a much stronger weld, taking 28 sledgehammer blows to break vs 7 for the ER70S-6. Results looked repeatable. e: I can find ER80S-D2 in 11# spools from a couple vendors. I also found that Crown Alloys sells 0.035" ER100S-1 in small spools. ryanrs fucked around with this message at 18:33 on Oct 19, 2022 |
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Oct 19, 2022 01:38
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