auxilary Posted December 15, 2004 Share Posted December 15, 2004 Cut out cancer today, most of the floor board frame rail. I cleaned up today (no pics) and evened out the surface. I got some rectangular tubing, 4 foot cuts for each side, in 3"x1"x48. I picked up two sets, 16 ga and 1/8" thick. I was originally planning on welding in 1/8 in, but I have a feeling it may be a bit too much for the stock floorpans with no reinforcement on top. Is there any reason I should use something that thick? I've decided to use the 16ga units. Should I weld in a flat sheet of 16ga steel to spread out the surface pressure area, or just weld them in directly? Did you guys coat the rails on the inside with any sort of rust protector like POR15? Do I drill out drain holes in case of moisture in the new units as well? Quote Link to comment Share on other sites More sharing options...
JMortensen Posted December 15, 2004 Share Posted December 15, 2004 I wouldn't paint them then try to weld, because you want the welding surface clean. I would weld them on, drill a hole or two, and use one of these http://www.eastwood.com/shopping/product/detailmain.jsp?itemID=10966&itemType=PRODUCT&RS=1&keyword=rust+gun to spray your POR15 or whatever inside the rail AFTER you weld. That's my plan on a lot of my rusty areas. Quote Link to comment Share on other sites More sharing options...
Jeff Posted December 15, 2004 Share Posted December 15, 2004 I used the 3"x1"x1/8" ones but I replaced my floor pans with 16 gauge sheet metal at the same time. I would think the 16 gauge ones would work just fine but while you're at it why don't you turn them into subframe connectors. Four feet of material won't be enough but it wouldn't be much more work and then you wouldn't have to worry about transfering all of the load to the floor pans. This is what mine looked like when completed. Quote Link to comment Share on other sites More sharing options...
auxilary Posted December 15, 2004 Author Share Posted December 15, 2004 Oh, I am. the main floor frame rail measures 47", and I got 2 x48" to fix that. I bought 3 x 4 feet so I could have extra left over to connect them to front frame rails and to the back crossmember Quote Link to comment Share on other sites More sharing options...
U.P. Z Posted December 15, 2004 Share Posted December 15, 2004 I made one out of 16 guage and welded it to the floor pan. The worst part will probably be cleaning all that undercoating and crap off. Also, make sure your carpet don't catch on fire if you weld to the floor pan. Quote Link to comment Share on other sites More sharing options...
CruxGNZ Posted December 15, 2004 Share Posted December 15, 2004 For what it's worth, I believe Ernie "RacerX" said that there is a weldable primer, just in case you want to hit the bare metal with something while you're working on it. !M! Quote Link to comment Share on other sites More sharing options...
U.P. Z Posted December 15, 2004 Share Posted December 15, 2004 Try this stuff www.picklex.com it works better than anything else I've tried. You can buy it here autobodystore.com. They also have a great forum for autobody work. I've used 3M weld thru coating before and the can ALWAYS clogs before you even get halfway thru it. Picklex will covert the rust and give you a weldable coating. Quote Link to comment Share on other sites More sharing options...
auxilary Posted December 15, 2004 Author Share Posted December 15, 2004 For what it's worth' date=' I believe Ernie "RacerX" said that there is a weldable primer, just in case you want to hit the bare metal with [i']something[/i] while you're working on it. !M! Since Ernie lives 20 miles from the shop my car's at, maybe I can con him into doing something. hahahhah UPZ: thanks, i'll check it out! Quote Link to comment Share on other sites More sharing options...
pparaska Posted December 16, 2004 Share Posted December 16, 2004 Hi Alex - thanks for the wake up email! 18 gage is a bit thin for this use. 1/8" is probably a better choice of the two. I'd go with the 1/8" of the two you have. Steel gage thickness as reported by manufacturers vary alot. Here's a chart I found, although I've seen 18 gage reported at .0451" versus the .0478" I see on this chart. I'd go with something like 12 gage at least if I had a choice. http://www.evergreen.edu/biophysics/technotes/fabric/sheet_metal.htm All the weld through coatings I've used burn off around the weld area and I'd think rust later. Zinc phospate coatings like what POR-15's metal prep and Eastwood's Oxi-Solv leave behind is good, but usually thin. If you have the car on a rotisserie, then spraying POR-15 (LOTS) into the closed cavity through holes and then spinning her around on the spit may distrubute the paint well. Quote Link to comment Share on other sites More sharing options...
Drax240z Posted December 16, 2004 Share Posted December 16, 2004 For what it's worth I wouldn't use 1/8" if it were my car. Overkill! 14ga would be a big improvement over stock, if you want to err on the side of overkill 12ga would be good. Save the weight and put it towards a good roll cage, but better return in stiffness vs. weight gain than sub frame connectors with increased thickness. Given the choice between 1/8 and 16ga I'd probably choose the 16ga honestly. I'm all for a rigid chassis, I just think the weight is better gained elsewhere. If your floorpans are also 16ga just weld 1" of every 2" and seal it super well. Use a weld through like these guys recommend, and try to spray inside the frame rail as well. Warning: Mild steel is usually coated with a wax, you'll need to clean that off AND rough the surface up if you want POR-15 to stick to it well. Make sure there is no way for moisture to get between layers of metal and sit there when you are done. (use seam sealer, undercoating, paint, or a combination to ensure this doesn't happen) Quote Link to comment Share on other sites More sharing options...
Roostmonkey Posted December 16, 2004 Share Posted December 16, 2004 The lighter ga. stock is fine if you can form some stiffening ribs into the panel.Thats how the factories can get away with the thin stock but a flat sheet is going to oilcan with welding and other stresses. Quote Link to comment Share on other sites More sharing options...
johnc Posted December 16, 2004 Share Posted December 16, 2004 Its not the thickness of the material that should concern you. Focus on the design of the structure. Boxes are stronger then channels and the floor pan can be one side of a box. Quote Link to comment Share on other sites More sharing options...
pparaska Posted December 16, 2004 Share Posted December 16, 2004 Good point, John. I was really referring to using 16 gage (not 18 like I wrote) instead of 1/8" for the tubing wall thickness. The tiny amount of weight increase you're talking about in an area where the Z is not very stiff seems a minor concern. When these cars rust, the front and rear ends of the inner and outer rocker boxes get mushy, and the car gets more flexible. That's why I added the floor board frame rails, and tied them in well front and rear - to provide a replacement path for bending and torsional loads on the chassis. Quote Link to comment Share on other sites More sharing options...
hat1324 Posted August 17, 2005 Share Posted August 17, 2005 BUMPING! My frame rail is ok but my floorboards are rusted through, i didnt stop to look as I started cutting but the rail that runs through the floor is also rusted, my question NOW is.. as I have allready cut the hell out of the floor as I planned to remove it(driverside) Should I just cut the floorboard framerail out, and make subframe connectors like the pictures posted? what will happen if I cut the floor out, and leave it overnight till the metal supply shop opens? Quote Link to comment Share on other sites More sharing options...
johnc Posted August 17, 2005 Share Posted August 17, 2005 You probably won't have a problem if only one of the floor pans are cut out. Its even less of a problem if the engine and transmission is out of the car. Quote Link to comment Share on other sites More sharing options...
hat1324 Posted August 17, 2005 Share Posted August 17, 2005 everything is out of the car, it sits on 3 wheels and a jackstand at the moment, One more Q while I have you lurking John, Is what about the middle rail for the seat? or could I cut it out as well(rusted).. I cant think of what its called, what is the rectangular tubing with circles cut out? Quote Link to comment Share on other sites More sharing options...
hat1324 Posted August 18, 2005 Share Posted August 18, 2005 ok for those of you that made the subframe connector, what about the sway bar mount that is in the exact spot of the rail? im going solid rear so probobly doesnt matter Quote Link to comment Share on other sites More sharing options...
Nismo280zEd Posted August 20, 2005 Share Posted August 20, 2005 any body have some larger pics they could send me on turning them in to subframe connectors, close up of the front, and close up of the rear woudl be great. Soureyecandy@hotmail.com Quote Link to comment Share on other sites More sharing options...
hat1324 Posted August 20, 2005 Share Posted August 20, 2005 I just made mine, the floors out so I can take any pic you want.. will be with my camera phone though.. what I did was go straight back from the front rail to where the pan rises, then went up at 45* then straight across to the rear frame.. _________________________/== ________________________// ======================= somthing like that lol.. forget the solid lines, spaces didnt hold out.. Quote Link to comment Share on other sites More sharing options...
Tim240z Posted August 20, 2005 Share Posted August 20, 2005 Here are some close ups of mine: http://tim240z.iwarp.com/photo3.html Quote Link to comment Share on other sites More sharing options...
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