I'll be attempting this for the first time very soon when I replace floor pans, inner rockers, one torque box, center trunk floor, then later inner & outer wheelhouses and quarters. I have no idea how well those cutters hold up so How many should I buy? Is there a difference in them? Harbor Freight has them manufactured by Drill Master for 3.99. I ordered one to get started from O'Reilly's for $11. It hasn't come in yet.

WhenI start using it do I drill from the top of floor pans? They don't go through both pans do they? Do y'all use electric or air drills?

I have two of the double ened ones (probably Blair). I have removed the floor on both sides, the trunk floor and drops and some of the panels around the rear window. I have one good side left. I don't use the cutters for every weld, some I used an air chisel others were cut with a gasket scraper and hammer. I use a cordless drill and run it slow. It really helps to punch or drill a small hole to keep the cutter from wandering. I try not to cut both sides but it's not the end of the world if you do, you'll need a hole to plug weld it back if you're using MIG anyway.

Jeff

Thanks for the reply but as I understand it if I'm drilling though the seat brace to be removed into say the tunnel that is to remain then I wouldn't want a hole through both right? I guess I could drill through the piece to remain first but then I'd have to weld from that side.
This will interesting.

I just removed the dash panel in my 67 Camaro. I bought the first spot weld cutter from Eastwood Co. The cutter has a spring loaded tip that fits in your guide hole and a double edge cutter that screws on. The cutter was cheap and I broke it drilling six welds. I did a search on the internet and bought a new spot weld cutter and a three pack of replacement cutters from SJ tools. This name brand is Blair. I finished this evening using the new cutter without breaking any. I used a 18V cordless drill. These cutters are sharp and you don't put much pressure on it. I can hear a pop sound when I drill through the first layer of metal. Sure makes removing panels easier.

Even if you drill through both panels with the small guide bit that ok, it is easy to fill with a wire feed. more work. But your right you do not want to drill through both unless you plan to weld from the underneath. Which can be tricky unless on a roto. Get a good bit, lots of oil will help to keep it sharp. Grind the circles off when panel is removed

I tried the special short drill bit type, the blair hole saw type....both were fair...by far the best I found was this type. http://www.eastwoodco.com/jump.jsp?itemID=14684&itemType=PRODUCT. Says skip proof but not "proof" I found that the easiest way was to drill a small hole ...say 3/32....thru both panels then use this bit with the guide pin in the hole. When welding up spots that small hole is no big deal to fill in. I also use a drop of light weight oil at each place and run that bit sloooow. Good luck. PS that bit may seem steep $ but if you have more than a few welds to do you'll be money and time ahead.

Dont' do what I did at first and use WD 40 to lube the cuts....could never get completely off metal and welding was a PITA.

Wow, WD40 was just what I was thinking. So what kind of oil? Something like sewing machine or air gun?

I have had two blair ones, the first one i broke the shaft cause the cutter was so extreemly tight. The second the guide pin shot out making it useless. Ive gone through a couple of the actual cutter pieces. Last time I ordered the one from harbor freight, and its the only one I will replace it with if I can ever manage to break or dull it. This thing has out drilled the other cutters combined.

The $3.99 ones from Harbor Freight? That's good to know. We have a new one just opened in town but they don't have them yet. I did pick up the one O'Reilly's ordered for me. It is by S&G Tool Aid.

Heres a short thread with some info on welding floors.. http://www.camaros.net/forums/showthread.php?t=95567

Brian

Thanks Brian. I've been reading a ton of your Basics. I'm going to use them as my play by play guide this weekend when I hook up the Miller 140 for the first time. Now I guess I'm going to be up half the night again reading. Oh well.

It was a short read. Thanks for the tip. Now I need to read up on weld thru primer. Do I put that on and if so when . Or is the new pans I buy already painted with it?

Just use the weld thru where ever there is bare metal, and have the minimum of bare metal you can get away with, that is the basic rule.

You clean the metal, epoxy prime it, then strip a dime sized area (or smaller) where you are going to weld, apply weld thru primer there and you are good to go. Don't apply it heavy, and let it dry throughly.

Do some test welds with this set up on some "coupons" and work with it. It IS different than bare metal so you want to know what to expect when you do your floors. Don't do all your practice on bare metal and then jump to weld thru primer, you will be frustrated very quick.

Brian

Heres the results of a little weld test. http://www.1969supersport.com/fintest.html

Rob

Page 2 and 3 of this section will show you a little more about spot weld drill bits. http://www.1969supersport.com/fp.html

Rob

Wow thanks. That was an education. I'm not sure I follow the marking of lines on the inner rocker for where the brace will go back. In my case I'm going to be replacing both inner rockers. Does that apply? I was thinking I'd be doing one side at a time and leaving the bracing attached on the other side so then all I have to do is bring it back to the same height on the new inner and weld it back on. Then do the same on the other side. Is that how I should do it?

Let me list how I think I should approach it and y'all let me know if I'm off track:

1. Clean floor or trunk pan of all seam sealer, jute backing etc.
2. Sand to identify spot welds. Can I use angle grinder (is there an appropriate wheel) or should I use a wire wheel or use 80 grit on a DA?
3. Center punch each spot weld and drill 3/32 hole all the way thru.
4. Use spot weld cutter to cut thru just the top layer of metal
5. Use putty knife and hammer to break the weld
6. Punch out holes in new pans (I'm still contemplating Martinsr's method of drilling them in place if I understand that approach)
7. Grind entire top of brace to clean it up
8. Paint it with epoxy
9. Grind around where the spot weld will be on the brace
10. Paint that area with weld thru primer (Can I just paint the entire top of brace with weld thru primer and not do 9 and 10?)
11. Set pan in place and press down on brace. Probably attach some screws to draw it up tight
12. Spot weld.
13. Grind smooth
14. Paint with POR15 or epoxy (Obviously I have a lot of reading to do on painting)

If you have a compressor an air chisel will be a handy tool to have for cutting through spotwelds, and in some cases won't leave the little raised circle of metal that a spotweld bit leaves that you'll have to grind down. I got an air hammer with five chisels for $7 at Harbor Freight and it has worked like a champ.

The other reason it's nice to have an air chisel is when you can't get a good idea where the center of the spotweld is located for the bit, just run the air chisel through it.

I bought two cutters from Harbor freights, sounds like the same ones you were looking at. I was very skeptical how long they would last but i've removed about 75 spot welds with only one and it's still cutting very well. Its key to use low rpm and i'm using 10w-30 oil during the cut. Overall i'm surprised its last this long. I would recommend using a center drill to initiate a start point or it will walk all over.

I do have a big 80 gal 2 stage compressor (or will have when a new pressure switch arrives). I bought an air chisel and air drill. I thought I'd see which works best.

Let me add a question about painting. To spray epoxy and weld thru primer do I need a spray gun or do they come in rattle cans? I anticipate buying a good quality spray gun when I get to the point of painting whch I intend to attempt also. But right now that compressor just has a regulator and water separator attached to it and I intend to run about 50' of pipe with drains and descant drier etc before then. So if I need to use the compressor before that can I buy a cheapo gun and run it right off the water separator for epoxy and weld thru?

3M weld thru comes in spray cans...epoxy has to be mixed with catalyst and shot or I have at times just mixed up a small amount in a cup and applied with a brush.

I bought a cheaper gun for all my primering, cost about $50 or so form HF I think....Once I get to actual paint, I'll use a much nicer gun ;)

Well I drilled out a half dozen on the seat pan. Went pretty well. CDMinter55: I did experience the pop you mentioned. I about jumped out of the car. I can see I need a center punch and the small guide hole is a great idea.
I had one problem. The top of the seat pan was lap welded on the edge to the tunnel. I used a cut off wheel to grind it down. I got impatient and used a chisel to finish breaking it apart and put a hole in the tunnel. My first repair patch is coming up.

Winch, on my website under floor pans there are answers to several of your questions, just don't use as many screws as I did, unless you have nothing but time, its way overkill and not worth it.

You will see how far to hold back from the plug weld with epoxy, the size drill bit and hex head screw that will pull the pans down pretty tight.

Different types of tools I used, butt weld clamps, cleco fasteners, a hodge podge of different stuff, it might give you some ideas.

I would probably put that air chisel in the drawer, and try and take the panels apart like you have to save them, minimal damage, slow and easy.

I give you a lot of credit though, you ask questions up front, thats the smart way to do it.

These are chevelle floor pans, but the same principle.

Good luck.

Rob

Wow thanks Rob. I've been reading and reading. I think the first thing I'll do this weekend, especially if my pressure switch doesn't come in, is to plumb the air supply lines in the garage. One question on that. If I have trouble finding a short piece of flexible 3/4 hose to go from compressor to black pipe can I connect directly to the compressor with black pipe? Is the only issue vibration? I have the compressor lag bolted into a 2x10 that is bolted to the floor band joist. It doesn't vibrate too bad.

Another question on air supply system: Is there a way to determine the amount of moisture in the air at the gun? Any kind of meter or trick so that I can tell how effective my system is?

Wow thanks Rob. I've been reading and reading. I think the first thing I'll do this weekend, especially if my pressure switch doesn't come in, is to plumb the air supply lines in the garage. One question on that. If I have trouble finding a short piece of flexible 3/4 hose to go from compressor to black pipe can I connect directly to the compressor with black pipe? Is the only issue vibration? I have the compressor lag bolted into a 2x10 that is bolted to the floor band joist. It doesn't vibrate too bad.

Another question on air supply system: Is there a way to determine the amount of moisture in the air at the gun? Any kind of meter or trick so that I can tell how effective my system is?

You will have some movement in your compressor, I would find a flexible hose, a hydraulic repair shop, and some automotive machining shops can do it. I give a description of the hose I used in the airline drawings.

I guess you saw this http://www.1969supersport.com/draw1.html

As far as moisture at the gun, if you have a die grinder or cut off wheel tool, you can usually run them a bit and the moisture will make your hand wet.

Be patient and put the airlines in as good as you can, I kept reworking mine to get them right. If your using black pipe, clean the threads with a little wire brush and lacquer thinner, then any tape or pipe dope will work if there clean, other wise you might be chasing some leaks down.

Rob

I started drilling out more of the seat brace spot welds across the back and it seems like I never get it all out. When I separate the two pieces of metal it is still welded all around the spot. Is that normal? How big are these spot welds? I'm using a 3/8 cutter. I'm afraid I'm distorting that part of the seat brace. I sure wish I had my compressor hooked up so I could try an air chisel there. It's got to be easier than his hand held.

Now I'm madder than a nest of hornets. I just called the company that I ordered my compressor's pressure switch from last week and they said because I used PayPal to withdraw from my checking account they were waiting for verification that it had cleared. I thought Payal was instant. So I updated Paypal to use my credit card and re-ordered the part and called that company back. They said they would refund the first one and ship it right out. I sure hope I don't wind up paying twice but as long as I get the switch I'll be happy. What really aggravates me is according to my bank the Paypal withdrawal was taken out the next day after I placed the order. GRRRR

Because you don't have any air yet, if you have a dremel tool, those little reinforced cut off wheels, I think five of them in a package. You could grind just a little around the edge of your spot weld to help break it loose, sure wish you had some pictures.

In this section http://www.1969supersport.com/flo.html pictures in part 3 and 4 you can see where I had to grind the side of the hole out around the spot weld and how you can fix it.

Do these help?

Those are good pictures, but its a Camaro and I'm not sure what I'm looking at, maybe somebody that has fixed this particular area could give you a little help.

That's the rear lip of the seat brace as it sits on top of the full length floor pan which in turn sits on top of the H brace underneath. I'm thinking this has been remove and replace before and they used large spot welds. They are way bigger on this lip than on the end where it attached to the rocker.
The dremel sounds like a good idea. I just bought one that is air driven! I guess I'll wait until I get my pressure switch or move on to another area.

You probably have looked at this thread, there might be something on it where he addresses that area, http://www.camaros.net/forums/showthread.php?t=121480 one other thing I use a carbide burr on a die grinder to help out a little sometimes on those spot welds. I'm sure somebody will see your thread and help out, hang in there.

I typed in camaro floor pan in the search and there a lot of threads on it, maybe something in there.

Thanks. I read a lot of those during the day while I'm here "at work". I just haven't seen any yet that address how large the spot weld can be.

OK I've been drilling welds for several days now and I'm getting the hang of it. I've been using an 18v cordless drill but what can I use if the area is hard to get to? Do those cutters work in a small air angle head die grinder? Seems like that would be too high RPM?

BTW I'm taking back several air tools I bought at HF. Central Pneumatic stuff is junk I think. I haven't used anything really good yet. The CP air chisel I've been using will separate panels but not cut much if the weld between them is tight or large.

There's no way around it, drilling all those spotwelds is just a crummy job, ain't it? I still think the chisel is your best bet for spotwelds in hard to reach areas. To each their own, but that's what worked for me. so many of the spotwelds were irregular in shape and size that I couldn't get the spotweld cutter bit to get a good bite and start cutting. Yeah, the HF tools are pretty hit or miss on quality, but I'm of the opinion that most of the stuff is okay for occasional hobbyist use. And if they only last for one job, you're still WAY ahead of paying someone to do the job. The chisels that came with my air hammer were blunt, didn't do a thing until I hit 'em with the grinder and put a sharp edge on them, then they cut great. Great for getting bushing sleeves out of suspension parts, too.

Winch,

I did some research and found that the ingersoll Rand die grinders are much better than the HF stuff. Shop around on the internet i paid $60 for a 90 degree and the same for zero degree. I wouldn't recomend using with the spot cutter unless you can control the speed.

My HF spot cutter finally broke and the local HF store ran out so i paid 3X at the local body shop and surprising it didn't last 2 cuts before it broke! Therefore jumped in the truck drove to the next HF store and bought another and now its lasted 20+ cuts without a hitch.

the only spot welds i have left to cut is the trunk floor and i was going to use my 1/2 inch drill with a 90 degree elbow. I'm not real excited to start it tonight...........way too many spot welds in the last couple weeks.

tony

The better spot weld drillers are harder metal and the edge lasts much longer. However, being harder they will break if subjected to hard use. I have broken them after a hole to two my self. But if you are careful they will last many, many welds. I have a "Spitsnagel" drill and the bit that it came with lasted literally almost a year! This was using it nearly every day in a shop! Now, this tool holds the bit perfectly straight and with the perfect pressure. But that just goes to show you how long these bits will last if used properly.

Autobodystore.com has some similar bits by Wivco.

Brian

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