Daily Body and Paint (P&B) Tips, a series

[tbirdtbird]

TIP #1

Want to try your hand at body work?

It is important to have a solid metal base under any bondo (plastic) that you use. We have seen gum wrappers, window screen, styrofoam cups, wooden sticks, and what have you underneath plastic filler. Your car deserves better! This is the first tip in a series.

[Mitch]

I saw a car with a piece of a STOP sign underneath the mud when viewing the panel from behind.

[Tom Wesenberg]

I remember my neighbor stuffing newspaper into the large rust hole in his 1960 Lincoln cowl, then mudding it up, painting it, and selling the car.

[BILL WILLIAMSON]

Chris did-manteled a Porsche rocker panel, stuffed with READABLE Classified Ads, from CINCINATTI---
Bill W.

[tbirdtbird]

TIP #2

Special tools needed:
The list could become very long so let's start with a few basics:
1. Air compressor, which most prolly already have. You will be using a cutoff wheel and a die grinder. Choose whichever brands you like, but many will argue that IR (Ingersoll Rand) makes the best air tools that will really hold up. Let the force of the compressed air do the hard work!
2. At some point you may want to invest in an air file , why kill your shoulders blocking filler (sanding filler) when the air is happy to do it for you!
3. A welder. Once you own a welder it is hard to understand how you got along without it. Miller, Lincoln....you choose. You want a MIG, with a bottle of inert gas. 110V machine will do sheet metal nicely, plug into any outlet
More on welders next tip

The cutoff wheel is a bi-directional Sunex, the die grinder is an Snap On

image000000.jpg

[Beauford]

I bought a 110 MIG...have no idea how to use it correctly but having fun doing some stuff like a grill leg...much like auto painting I need practice.

[tbirdtbird]

that is excellent. It matters not where you start, it only matters that you did start!

[plyfor]

Great tips, thanks. Ditto to clean metal base with no rust for very thinnly applied bondo to work. Also, we've found the lacquer based tube putty to not be suitable for much due to shrinkage other than very superficial scratches.
Other important items to consider: well-fitting respirators, masks, gloves , etc.to minimize the toxic chem's absorption. A lot of the newer supposedly low VOC formulations can be misleading and contain nasty compounds.

[tbirdtbird]

TIP #3

Welders. TIG is mostly out of the skill range of the hobbyist, and no worries, MIG will work just fine.
You can run a MIG machine with or with a bottle of Argon-CO2. If you do not use a shielding gas, tho, you would need flux-core wire. There is a problem with this, tho. Flux core wire gives sloppy welds and the acid flux will end up destroying your paint job no matter how well you attempt to clean it up. Think fence post welding if you are using flux core wire.
By reversing 2 wires inside the welder, it can be converted to shielded gas. You will get way better welds. Welding is something that if it looks good it IS good.
Many body shops prefer .023 wire for sheet metal. The rule is the thinner the metal the finer the wire. You will have an awful time welding sheet metal with .035 or .030 wire. As with most shops, we prefer a brand called Easy Grind, in size .023. It is a dream to weld with, and easy to use.
https://weldingsupply.com/cgi-bin/ei...DEF:OR:130PS43
Which brand welder? You choose. Miller, Lincoln, are established brands. Harbor Freight sells them but I have no knowledge of their quality.

[Mitch]

This is really great information thanks.
So when putting in say a patch panel do you just install it with little tacks spaced apart? Some welders have a spot tack setting correct?

[BNCHIEF]

Tbird i was gonna mention never ever use flux core wire, do it right or not at all.

[dmdeaton]

tbird, do you ever gas weld panels? I watched some demos with the low pressure setups.

[tbirdtbird]

Not me, I don't gas weld well. It is not a bad idea, tho, since you have eliminated the harder weld bead you get with MIG.
And even gas welders will tell you MIG is faster

[BNCHIEF]

Tbird exactly as you say my big Lincoln has a set up where it can spot or stitch weld which is what I have used, old body guy taught me to lead can be fun or frustrating, your choice.

[tbirdtbird]

TIP #4

OK you got your welder, what now?
Dig up some scrap sheet metal ("tin"), or go to a junkyard and grab an old fender, get down to bare metal, and start practicing. You can learn to MIG in 30 minutes with a mentor, it is really very easy. Start by welding in the center of the fender, when u have that down, get two pieces of tin and weld the two together along the edges, this is a little harder. Don't be afraid to experiment with the heat settings. Your gas bottle regulator should be set to about 12 psi. If there is a lot of wind, get behind a windbreak, the wind will blow the gas away. If needed, in a windy situation, we will crank the pressure up to 20 or 25 psi. Be sure all flammable liquids, rags, etc are no where near your welding area

[Mitch]

I learned how to mig on friggin exhaust pipe, that makes it easy huh and i keep my gas set at 36 to much? a welding shop told me to use that setting

[Corley]

Not to get too picky, but shieding gas regulators output is generally rated in CFH, not psi. CFH - Cubic Feet per Hour. ( If you were to shoot 12 psi of shielding gas down to the mig torch, you will soon find your bottle is empty.)

[Tom Wesenberg]

I learned how to mig on friggin exhaust pipe, that makes it easy huh and i keep my gas set at 36 to much? a welding shop told me to use that setting

That's because they sell the bottle of gas. LOL
I set my pressure many years ago and haven't touched it since. I just welded my lawn mower gas tank bracket yesterday, and I think I have it set for 15 lbs. I'll double check the next time I weld something. A year ago I welded something and forgot to turn the gas on. I was wondering why it was welding so crappy. LOL

[tbirdtbird]

"That's because they sell the bottle of gas. LOL"

yep

[pAAt]

I was using a lot of gas with a regular dial gage and decided to try this type. I'm using a lot less gas now, but my other gage might have been k-put from the beginning.

[Mitch]

Well NO they don't sell the gas their a fabrication shop only..they are proffesional welders tho. . i guess i can google search it but can anyone answer my question

[BNCHIEF]

Mitch 15 is all you should need max.

[pAAt]

Mitch, your question is 36 to much ? I'd say yes unless your gage isn't reading right or leaking. Weld a bit turn and keep turning it down util you notice your weld getting shitty then turn it up a hair. IMO only !!

[Mitch]

I have been using 36 for 25 years . My welds are perfect
We dont do a ton of welding just mechanical stuff, were not a body shop..
My tank lasts about a year and a half or more

[pAAt]

Sounds like you have it figured out pretty well then, I should have known !! Pat's cheep

[tbirdtbird]

no such thing as too much gas, only too little. Dial it back like Pat says until the welds are crappy then you'll know for sure with your setup, including your particular gauge. I have never seen anything in print. I use 12 on a daily basis since that is what my welding supply shop told me 30 yrs ago when i got the rig. A tank per year is not at all bad, tho!
We use waay more than that since we are constantly welding something here

[Mitch]

Thanks Tbird

[BNCHIEF]

Mine is set at 15 if you have doors open or some circulation it may need a higher setting to keep from losing your shield for the wire.

[Dennis]

I have welded with a MIG in the past and decided a couple months ago to buy a TIG. They are beginning to get a lot more affordable, but still pricey. I can stick weld, or TIG steel, aluminum and stainless. AC or DC. Some machines are being made to do stick, MIG, and TIG but they are only DC. The machine I bought can be ran on 110v or 220v. It has an adapter cord for the 110 but is limited to amps output on 110v. TIG appealed to me years ago when I was working in a shop that bought a Miller that was adapted to the stick machine. It wasn't as sophisticated as the machines today but was a clean weld machine. There are some good video clips on You Tube, weldingtipsandtricks.com Some clips are MIG others are TIG.

[BILL WILLIAMSON]

Welding is like COOKING, there are NO REAL RULES, experiment & find out what works for you!
Bill W.

[tbirdtbird]

TIP #5

OK, some tricks for tin.
Especially when mastering the skillset for tin welding,
1) weld with the workpiece horizontal. Later you will be able to do vertical. You can often reposition your work so that it is horizontal, especially practice pieces.
2) Weld by triggering. Rather than having the MIG trigger squeezed constantly as you would for thicker metal, squeeze momentarily, laying down a short bead, then let go momentarily until the brightness of the weld puddle has all but faded, then squeeze again, and keep going like this, on-off-on-off etc. This is called triggering, and will prevent burning thru the thin metal. It is a way of controlling the heat. With practice, these welds will look like they were done continuously.
Try it.
Another tool: at some point you will need to grind your welds smooth, and not dig into the parent metal. A right-angle air grinder is the perfect tool, and if you fit it for Roloc discs you can fly. This system allows quick change of grinding discs
image000000.jpg

[tbirdtbird]

Tip #6

The first rule of painting is to apply three coats, since you will color sand off 1 coat. 1 coat is about 1 mil thick. That leaves you 2 mils for protection. If you do not have 3 coats on there I would just leave it alone, else you might easily go thru.

There is buffing and there is color sanding. Two very different things. Color sanding involves wet sanding with a soft pad made for the purpose (never your fingers) starting at 1000 and working your way up slowly to 3000. The darker the color the higher the grit number has to be. Great care is required.

Buffing alone will not remove the orange peel, it must be wet sanded first. Wet sanding smooths it all out, but makes it dull. Buffing using a stepwise series of buffing compounds brings the shine back.

Not all of the orange peel needs to be removed to significantly improve the appearance, which is little known. You certainly CAN sand out all the peel, but if the paint is thin in some areas you may go thru. An experienced shooter can lay the paint down with very even uniform coats and not worry about thin spots. BTW 1 coat means with each pass of the gun you overlap the previous pass by 50%.

Without seeing it, from what you have described, I would carefully wet sand with 3000 grit (it feels more like tissue paper than sandpaper), only in the problem areas; I would not try to remove all the peel; then buff. Should there be interest, I can later delineate what buffing compounds and pads we use here. But some type of electric or air-powered buffer would be required. Be absolutely certain that the container you use for water is extremely clean, and without any dirt or grit that could mar your work. And if you go up stepwise from 1000 to a higher grit you must thoroughly clean the container before going to the next grit.

YouTube can be helpful but there are also some bad YouTubes out there. And when your acquaintances tell you to 'just buff it out' I would wonder how many of them have actually done it themselves.

Should anyone be wondering what expertise we bring to this topic, please be aware that my nephew and I have a private paint and body shop, complete with paint booth, and have done collision repair and entire body shoots on at least 50 cars. I myself have painted or repainted at least 25 entire cars.

A trick we use to reduce orange peel is to add a bit extra reducer to the final coat. This results in a remarkably peel-free finish. Of course, this is a double edged sword, as more reducer means a greater chance of runs and sags. Peel generally means the atomization of the paint is not complete. It is too thick, or the gun pressure too low. Proper flash time between coats is essential, and we modify flash times based on the prevailing temps.

[Standing Elk]

Thanks fellas for the advice, I am now armed and dangerous LOL One more question, when I wet sand with the 2500 + paper do I go about it just like block sanding only with very light pressure? Thanks again

[tbirdtbird]

Correct, it won't take much. Be sure you have good lighting and be sure to wipe dry with a paper towel often so you can see your progress. It is very hard to tell how much peel you have removed if the surface is wet

Here is a link to the soft block you want. It has a soft side and a slightly harder side

https://www.amazon.com/Motor-Guard-SB-1-Flexible-Sanding/dp/B003WUYG1E/ref=sr_1_1?ie=UTF8&qid=1521905952&sr=8-1&keywords=motor+guard+SB1&dpID=419wKSC0xOL&preST=_SX300_QL70_&dpSrc=srch

[Standing Elk]

Ok thanks again to all. I looked at it again this morning and it looked really pretty good. Still a little orange peal and a few specs of dust but not bad. I will wait a couple months and make the decision then, whether I will go any further with it, but I am thinking that I probably will if for no other reason than to learn. Thanks again

[tbirdtbird]

Since you are not in a hurry, why not take a chunk of sheet metal and shoot it and let it harden up for a month in the sun and then practice on that?
Why practice on the real deal

[BNCHIEF]

Excellent advice x2

[SeaSlugs]

heh, at a certian big yellow earth moving company they set thier hand welders 27v 350in/m on low 32v/450in/m on high @ 40-45 gas flow using .045 wire. welding robots runnin .052 wire were 70 for gas flow. and yes you can have too much gas as it can blow the weld puddle away and look like crap - yes too little it looks like crap as well haha.

and i learned just because a weld looks pretty it can be a batcave underneath and might as well be glue and paper mache in strength.

I need to get a bottle of argon for our lincoln 110v. Currently using flux core wire and did not know that about sheetmetal and painting it. I've just used it to hold crap together with a rattle can paint over it.