I was practicing doing rosette welds in preparation for some rust repair and can't seem to get good penetration.

Just to be clear; the patch piece has holes drilled in it and I am trying to rosette or plug weld through those holes to the area I am patching. I have attached a picture of one of my practice pieces. I'm using a Millermatic 135 with .024 solid core wire and 16ga sheet.

I have tried the highest voltage setting and I can still pull the two pieces apart. The holes get filled but the weld metal is barely going into the piece I'm attaching to.

Any suggestions? And, yes I did check the polarity.

Bigger holes?

Try checking your amps to the welder. You might have to much draw on the whole circuit. Also, a too long of extension cord will also limit your max. amperage.

Something else to look at is your wire feed speed. More juice requires more wire to get good penetration.

I bet you are trying to start your weld at the edge of the hole and trying to circle around the perimeter of the upper metal to fill.

Try this, start your weld in the center of the hole at the base metal (not touching the metal with the hole) - weld at the center for a second or so and as it starts to pool up, swirl the perimiter to fill.

I'm not using an extension cord. It seems like when I increase the wire speed I fill the hole too fast.

I was thinking the same thing as Travis. Start in the middle of the hole to get a good puddle in the base metal underneath, then work it around to the top piece.

Clean the sheet better and maybe scuff sand it.

Yes weld "out"start on the bottom ply, and weld out

Agree with other comments, start the weld int he middle of the hole, so the underneth metal is melted first, then work your way out . You'll need to play with the volts and amps setting (wire speed). As other poster noted, long thing gage extension cords can casue problems.

Be sure metal is degreased and rust free (looked clean in photo) Also to much inert gas can over cool the weld so make sure the Argon /CO2 flow (that mix works good on auto body) is optimal.

The type of weld you are doing will look very nice, just takes lots of practice and experimentation with the settings.

I tend to use 3/16 to 1/4 inch dia holes for this type of welding.

good luck

The previous posters are right.

Welding was my trade for 30 years....Rule #1...Always weld from the inside out. This rule always applies. It forces the expansion of the metal to the outside of the job, and minimizes distortion.

The photos show too much wire not enough heat. The finished weld bead should be much flatter, and not sitting up proud. Since you are practicing, back off the wire speed and crank the heat up enough to burn through the base metal. You've got one extreme (no penetration), go to the other and zero in on the correct settings.

3/16" or 1/4" is not big enough, you need to go with more like a 3/8" hole, or you'll fill up the hole before you get penetration on the base metal.

Can you get good welds on the base metal alone? Make sure you can get good surface welds with sufficient penetration before you fishplate over the base metal. It looks like the base metal may have a coating which could be causing weld penetration problems.

Are you clamping the pieces together? That makes a difference, the heat will separate the two pieces you are trying to weld.

Practice, practice, practice! You are smart! Too many guys do three welds and think they are proficient enought to start welding on the car.

Thanks for all the good advice.

I was thinking it was too much wire not enough heat also, but I cranked the voltage all the way up and still couldn't get good penetration. I even tried to blast through the base sheet, for a few seconds, and couldn't. It got good and hot, but I didn't blow through. As a beginner I figure I'm doing something wrong if I stray too far from the recommended welder settings. For 16ga. the recommended settings are 4.5 volt/60 speed. For 1/8" it is 10 volt/75 speed. The maximum volt setting is 10 and the maximum speed is 100. I even tried 10volt/60 speed and still felt like I was getting too much wire. Would it make sense to turn the speed down even more? How close to the recomended settings should I be?

I did try to start my weld from the middle, but the hole fills too fast and my aim's not so great. I think Santa is brining me an auto-darkening helmet...so that should help.

I don't think the metal is coated, but I'll give it a good clean with the grinder and see if that helps.

Not sure if I'll get to it tomorrow. We celebrate Christmas and Hanukah in my house so it's going to be a busy day!

Hope everyone has a happy Holiday! Thanks for the help.

[Too many guys do three welds and think they are proficient enought to start welding on the car. ] insert blushing smilie here.

Not to sound like a smart a$$, but are you sure that metal on the bottom is steel, maybe it's aluminum or stainless.

your gas pressure shouldn't be more than 10 to 15 lbs. as said earlier to high of pressure will cool or even snuff the weld.

one thing i found out working as a welder , and from personal experience on my own cars, is disconnect the battery- it messes with the weld polarity and pretty much turns a nice weld into what we call " bubblegum that looks like it was spit on as a weld " heheh

if you can , get a piece of scrap same thickness and practice on it with adjusting the feed and juice - myself i dont even watch the weld when adjusting it- when its right it will more or less sound like bacon sizzling - once it seems to sound right try a few practice weld beads to see how it flows - fine tune it from there

and yea it might take a bit to get it right- also depends on what type of welder your using- AC welders like say a cheap little 110 mig usually wont put out enuff heat for a real good weld

argon is a good shielding gas but is more expensive than CO2- at work we use a 75/25 argon /CO2 mix but for the person welding at his home you can probly go straight CO2

oh yea, id go with a 1/2 inch hole if you can- will be a lot more solid and effective and wont really be that much extra work

I am using 75/25 gas and the battery is out of the car.

Making bigger holes sounds like a good idea.

My main concern now is if it's ok to stray so far from the recommended welder settings?

Go with what works, the reccomended setting are guidelines only. Remember, you are welding 16gaX2.

That base piece looks like it has a coating on it, maybe the ground to it is bad. Which type of polarity are you running?

Mark

What polarity should mine be set at for 16ga. mild steel?
:PERMAGRIN: Joe

From everything I'm reading here it sounds like maybe your welder isn't working properly. It might be worth checking out before you get totally frustrated.

I'm using reverse polarity(direct current electrode poistive), as the manual recommends.

I gave the metal a good cleaning, drilled some bigger holes and clamped the pieces up real well.

Are both pieces the same metal? I see dark metal on the base metal, in the holes. You want everything to be shiney.

I used the max voltage setting and pretty low wire speed (4.5) and turned the gas pressure down to 15, I was using 25. I got good bacon sizzle and had time to start my weld in the center of the hole and work it out to the edges . I feel better about these welds. What do you think? Here's a pic of the front:

here's the back:

QUOTE (9146986 @ Dec 26 2005, 11:22 AM)

Are both pieces the same metal? I see dark metal on the base metal, in the holes. You want everything to be shiney.

...just bad photography...it was all clean and shiny

Thank you.
:PERMAGRIN: Joe

Shove a screwdriver between the metal pieces and go as far as you can towards a weld ....

Bend the metal up to see the size of the weld holding the 2 together.....

If you have a large point of attachment.....

Then tell me your settings, hole size, so I can try it on my Miller 135 in the next few days.

Ken

I've had the same problems, especially if the pieces have weld-thru primer on them. I opened up the holes and had better luck. I've also drilled a smaller hole in the base metal, thinking it would assist in the penetration of the bottom piece. I'm not sure if this is recommended, though.

QUOTE (elocke @ Dec 26 2005, 07:41 AM)

I've had the same problems, especially if the pieces have weld-thru primer on them. I opened up the holes and had better luck. I've also drilled a smaller hole in the base metal, thinking it would assist in the penetration of the bottom piece. I'm not sure if this is recommended, though.

Good idea with the smaller hole. Hobby welders are a trick to get working. Once you find out what works be ready to adjust your method as conditions change.


The photo of the back side of your test piece looks much better. A small bump is visable showing penatration.

QUOTE (kwales @ Dec 26 2005, 11:38 AM)

Shove a screwdriver between the metal pieces and go as far as you can towards a weld .... Bend the metal up to see the size of the weld holding the 2 together..... If you have a large point of attachment..... Then tell me your settings, hole size, so I can try it on my Miller 135 in the next few days. Ken

I did try to pry the pieces apart and for the first time I could not get them apart! Looks like they are attached pretty well.

I used 100volt/5speed, .024 solid wire, 16 ga, 75/25 gas set to 15cfh. 5/16" hole.

from pics of both sides it shows good penetration - might need a bit more wire - but looks good. id say run the weld just a wee bit slower maybe . since its a test piece tho the screwdriver thing would be one way to test it out


weld should have a slight mound to it when its just right, looks like yours has just a slight undercut to it , slowing the weld would probly fill it in that bit more you want but from the look alone id say you wont be able to rip it apart with the screwdriver

just about anyone can weld, i can teach a person in 30 minutes how to weld, rest is just constant practice.practive makes perfect, once you have the basics down its just all practice, even after working as a welder for the last 18 years im still doing that. and im certified in stick , mig, flux core, inner shield , outer shield , sub-arc, tig, oxy-acetylene,plus a couple others i cant always remember off hand lol

have built everything from work bench tables to a test ramp 40' by 12 ' with a vertical slope of about 15 degrees to a 200,000 gal water storage tank, heck ive even welded x mas trees one year heheh

That looks better!

Now do about 30 more!

When I learned how to TIG, I spent the first ten hours just making surface beads.

Moral of the story; you can't practice too much

Scrap metal is cheaper than Porsche metal!!

QUOTE (lincoln @ Dec 26 2005, 12:05 PM)

from pics of both sides it shows good penetration - might need a bit more wire - but looks good. id say run the weld just a wee bit slower maybe . since its a test piece tho the screwdriver thing would be one way to test it out...weld should have a slight mound to it when its just right, looks like yours has just a slight undercut to it , slowing the weld would probly fill it in that bit more you want but from the look alone id say you wont be able to rip it apart with the screwdriver

I'm confused by this response...for more wire I'd slow down the wire speed? Not sure what you mean by slow the weld down. Is it possible I have that undercut because I'm welding on a vertival surface? It looks to me like gravity is pulling the weld mound down a little.

The saga continues...

I'm pretty confident that I'm getting good penetration now. I'm using bigger holes, less sheilding gas, and I think I've got my volt/wire speed sorted out. I practiced on about 25 holes and was happy with the results...so I welded a piece in. When I ground down the welds I found some of them had these little holes. A few of my welds sort of bubbled (or swelled?) as I finished the weld. I'm not sure if they were the ones that have the little holes in them, but it seems logical. What are these holes? Should I be concerned? How do I avoid getting them?

That may be from the oxidizers in the welding wire doing it's work, so maybe getting the metal a little cleaner? Just a guess

the pieces were clean...the patch piece was painted with Bloxide (weldable primer)

also, hold the welding top over the weld for a couple seconds after you finish the weld. There is still shielding gas coming out for a few seconds. But I bet, you need a cleaner surface.

Also, try it without the weldable primer, even though it is weldable - it may not produce great looking welds

OK...I'll try to clean better and no more Bloxide. I didn't have it on my practice piece and that looked pretty good. I never was really sold on the weldable primer anyway..seems to me that it just burns off when you weld anyway.

I agree on the weldable primer. But if you have a big panel that you are sandwiching, i can see it's merits (more space between welds where it won't burn off). After all you are making the metal 2,200 degrees to weld

...so should I be concerned about the welds that have these little holes? Does it make sense to weld over them again so I get a smoother finish?

if it was a structural piece, I would say yes, those little holes are stress risers. If you are doing let's say a inner long kit, I would think those would be OK. That is just my thought, maybe right and maybe wrong

its called porosity- and one source of the problem could be the primer- we in the field only usually get that when shielding gass gets blown out of the weld or we run out of gas- id say set your gas at maybe 25 and after you let the trigger loose after the welds done just hold the nozzle over the weld an extra second

if it was say a steel building support beam like in a skyscraper id say grind it out and reweld

for a sheetmetal repair like your doing tho it should be ok


and yes if you want to you can weld over em to get a better finish - but your more likely to get the porosity still

maybe practice more til you can get the little holes heheh to dissappear

Why did I get the bubble effect on some welds and not others?

...also, what's the deal with the bubbling effect I got after the weld was filled? I started my weld at the center of the hole and then filled out around the circumference of the hole, as I finished filling in the weld and let go of the trigger the center of the weld sort of swelled up or bubbled out. Some even formed a peak or nipple. It seemed to happen randomly...no pattern. Most welds were nice and smooth with a low raised bump. Maybe 1 out of every 5 or 6 of them bubbled out like this.

The above answers are correct, the bubbles you see are porosity. What cause it are gasses escaping the weld puddle while it is still liquid.

Things that cause porosity are unclean surfaces, moisture, oils grease, contaminated flux (doesnt apply in this application), and deleterious materials. Also inadequate shielding can cause porosity.

I have never had much luck welding though "weld though Primers"

I dont know why you think reducing gas flow will help your welds, that is actually counter intuative, the gas creates the welding environment.. set the gauge at about 18-20 psi, if you have drafts, set it a bit higher.

I think that Miller recomends 23-25lbs or something with
.023 wire and Argon/O2 mix, check the recomendations on the welder

a common rul for welding is you should optimally try to keep the contact about the distance away from the material weldings thickness. that is if your welding 1/4 inch thick steel should be bout 1/4 inch away- this isnt really true tho

look at the nozzle- the tip should be about 1/8 inch inside the nozzle and try to keep the nozzle no more than bout 3/8s inch from weld

if your only having this problem intermittantly id say you are possibly letting your welding hand stray back away from the weld a bit

this happens because with the hood down you lose your equilibrium somewhat

try this- drop your hood without leaning against anything - notice how you sorta sway a bit?

anyways to limit the swaying effect a lot you should brace yourself by leaning on something or against something, for example if you just rest against the side of the car your welding on slightly- basically its just to steady yourself to decrease the swaying so you get a steadier weld

if at all possible, try to find a shop local to your area and ask if you can observe someone welding - also many welding supply stores have demo events or workshops you can try to get in on

Weld through primers work really good when you are using a spot welder. Lotta research in developing them for that process. The primer is rich in zinc and when you spot weld it the zinc migrates away from the weld area. This forms a ring of melted zinc around the welded area and provides excellent rust protection. Having weld through paint on the rest of the panel isn't a bad thing and controls corrosion...

That being said, this rosette process is a bastardized attempt at producing a spot weld with a MIG welder (no clamping pressure like a spot welder). So yes, I would expect a difference in the weld and possibly diffferent issues with the primer.

Personally, I think that the rosette welds have more weld surface area than the spot welds. More area, stronger weld. Adding a few holes to the weld spot weakens it some, but the weld area IS greater and should cause no problems.

Lookin good.

Ken