|
|
After practicing Oxy/Fuel Welding the last 3 months about twice a week most weeks, I have made little improvement. I confess I am disappointed with my progress, especially in the use of filler rod. Most of my welding looks welded, but they fall apart when put to the ball peen hammer stress test. especially if i add filler. There have been some days where my welds have held up to the street test, but mostly a few bangs and they fall off. I guess I will have to practice more. I have practiced with mostly shim metal of 14 ga or thicker because that was the only scrap i could get. the reason I am posting is about the metal i will be using for my project, mild steel-16 ga 2in square tubing. I have a 2 foot section to practice on and when i have practiced on it. its been mostly a disaster. I use a size #0 tip. the problem is the tubing is melting before I can weld it. As soon as the molten puddle comes, a hole has already started, I cant believe how quick it melts. Is there anyway I can control this?thanks.
Reply:Saying you have a #0 tip isn't enough information. You also need to say which manufacturer. Assuming Victor, then refer to this chart: (will read better with fixed-width font)VICTOR WELDING TIPS (data covers W, W-1 and W-J series tips) (types 1,4,13,17)Metal Welding Drill Pressures (psig) Consumption (scfh)Thickness Tip Size(in.) Size Oxygen Acetylene Acetylene--------------------------------------------------------- 1/32 000 75(.022) 3/5 3/5 1/2 3/64 00 70(.028) 3/5 3/5 1½/3 5/64 0 65(.035) 3/5 3/5 2/4 3/32 1 60(.040) 3/5 3/5 3/6 1/8 2 56(.046) 3/5 3/5 5/10 3/16 3 53(.060) 4/7 3/6 8/18 1/4 4 49(.073) 5/10 4/7 10/25 1/2 5 43(.089) 6/12 5/8 15/35 3/4 6 36(.106) 7/14 6/9 25/45 1¼ 7 30(.128) 8/16 8/10 30/60 2 8 29(.136) 10/19 9/12 35/75 3 10 27(.144) 12/24 12/15 50/10016 ga. is about 1/16", which is 4/64". Halfway between a 00 and 0 tip. So using a no. 0 tip isn't too far off. But I'd try going to a 00 tip. Also, go to the low end of the gas pressures in the chart. You want a cooler flame, which leads to a more controllable situation.The other thing you can do is to use thicker welding wire. When you stick the end of the wire into the pool it cools the pool down. The thicker the wire the stronger this effect. Also work harder at keeping the tip in the pool more often. Practice just heating a spot on 16 ga. scrap, and moving the spot without any blow-through. It may be that you are simply moving the torch too slowly.Finally, try to get some time with someone who is skilled at gas welding, ideally a teacher. Nothing like being able to see someone making mistakes for telling them the correct things to try.metalmagpie
Reply:like metalmagpie said.. you are too hot/too long in one spot..are you using a circling torch motion? try lowering gas pressures a little at a time, make sure you are neutral flame...
Reply:thanks very much metalmagpie and weldbead! i will try your advice. I wish I had a different oxygen regulator. the readings are difficult to be accurate with because the dial goes "0", then a bunch of notches, the next number is 40. i can guess where 10 is, but getting an accurate reading under that, especially something like "3" is difficult. The Act tank is easy to read. Are all the oxygen regulators like that? I will have to check next time I am at welding supplies. The welding rod tip is particularly useful, but that is exactly what i have been having so much trouble with. Need lots more practice. Taking a class is the last resort if all else fails. I would have to save up the money, and not having a car, I am not crazy about taking a bus at night in the winter. Originally Posted by metalmagpieSaying you have a #0 tip isn't enough information. You also need to say which manufacturer. 16 ga. is about 1/16", which is 4/64". Halfway between a 00 and 0 tip. So using a no. 0 tip isn't too far off. But I'd try going to a 00 tip. Also, go to the low end of the gas pressures in the chart. You want a cooler flame, which leads to a more controllable situation.The other thing you can do is to use thicker welding wire. When you stick the end of the wire into the pool it cools the pool down. The thicker the wire the stronger this effect. Also work harder at keeping the tip in the pool more often. Practice just heating a spot on 16 ga. scrap, and moving the spot without any blow-through. It may be that you are simply moving the torch too slowly.Finally, try to get some time with someone who is skilled at gas welding, ideally a teacher. Nothing like being able to see someone making mistakes for telling them the correct things to try.metalmagpie
Reply:look on a site called tinmantech... there is a description there of a method to set up a torch that does not require using the gauges ...
Reply:Like weldbead said, use the lowest gas pressure that gives you a nice flame. What you want is a soft fairly concentrated flame that by its own gas pressure won't blast a hole in the metal. Tip size is something you just have to kinda figure out by using the guidlines. When gas welding you generally want to keyhole as you go. This means actually melting enough that you are producing a hole and then dipping filler into the edge of the hole to move it all along. Don't be afraid to pull the torch straight up and away from the metal. This will remove that concentrated heat but still cover the area so it doesn't oxidize right away. While moving along you may have to constantly be pulling torch back to control the heat input. Thicker metals usually isn't an issue but 14g and thinner you usually have to melt a little and let set up then melt some more depending on joint configuration. Once you blow one of these holes I say you should practice filling it up as that will give you the ability to practice heat input. Don't just try and weld joints. With gas welding you can actually bridge gaps and fill holes very easily although obviously all joints should be a good fit or just a slight gap as to get better penetration or allow keyholing. One other thing is the gauge pressures as long as kept low are usually not super important as you can set the flow at the torch but some of the gauges that only read the higher pressure I have heard they can flutter or produce and inconsistant flow at lower pressures which may also lead to problems.Millermatic 252Lincoln 175 plusTA 185tswTA 161stlhypertherm pmax 45Victor torchHenrob torchAn S10 for each day of the week
Reply:Originally Posted by mimoosethanks very much metalmagpie and weldbead! i will try your advice. I wish I had a different oxygen regulator. the readings are difficult to be accurate with because the dial goes "0", then a bunch of notches, the next number is 40. i can guess where 10 is, but getting an accurate reading under that, especially something like "3" is difficult. The Act tank is easy to read. Are all the oxygen regulators like that? I will have to check next time I am at welding supplies. The welding rod tip is particularly useful, but that is exactly what i have been having so much trouble with. Need lots more practice. Taking a class is the last resort if all else fails. I would have to save up the money, and not having a car, I am not crazy about taking a bus at night in the winter.
Reply:Probably not accepted practice, but for 40 yrs i've always held the flame at a low angle in relation to the thin metal being welded. It helps me control the amount of heat. As the thickness of the metal gets greater i place the flame at a greater angle to input more heat. I hope i've made this understandable. MikeOl' Stonebreaker "Experience is the name everyone gives to their mistakes"Hobart G-213 portableMiller 175 migMiller thunderbolt ac/dc stick Victor O/A setupMakita chop saw |
|
发表于 2021-8-31 23:31:10