Minitub question with picture

[mopowers]

I just started minitubbing my 66.  The frame is a C-channel and when you grind the side of the frame to make the inner tub sit flush, it separates the frame from the floor pan.  Do I need to weld the floor back to the frame, or can I just weld the inner tub to the frame then weld the floor to the tub?  I'm sorry if this is a stupid question, this is my first experience minitubbing a mopar.  Thanks for the help.  I'll get a picture very soon.

[mopowers]

Here are a couple picture to help explain my question.

[cochez]

I think they all do that...I beleive the floor is just spot welded to the flanges....I tack welded mine at the seam and were the mini tub meets it...

[rpmrich]

i rewelded mine all the way. then just ground it back down smooth. it felt stronger,

[bOb shingler]

i welded the tub to the frame then welded the floor to the tub.

[Ryan (Strange246)]

i welded the tub to the frame then welded the floor to the tub.

  thats how i did mine...

[Halfaed]

i welded the tub to the frame then welded the floor to the tub.

  thats how i did mine...

Same here! Then I smeared seam sealer on it all to hide the crappy job!!!!

Looking good!!! I guess we don't have to tell you how important it is to get everything cleaned up before you weld it!!!!

[b569rr]

 

Weld it to the frame and then up top to the trunk floor. It will be good and strong.

Tom

[mopowers]

Thanks guys, I thought it would be over kil to weld it solid before weld the tub in.  The frame thinner than I thought.  I tried welding it and burned through on the lowest setting on my Lincoln MIG..  Do you think I need thinner wire, maybe .025?

[b569rr]

You will have problems welding the top side with .030. Use .023 and wash it side to side just a little bit to move your heat. .030 should be fine inside the wheel well tying the tub into the frame keeping most of your heat on the frame.

Tom

[mopowers]

Do I have to weld it solid or can I just weld 1" portions a few inches apart?  Then slap some polyurethane seam sealer over all the joints.

[b569rr]

I'm sure that will be fine. But I prefer to weld all of it. I like to have the weld be 99% of the sealer. Stitch weld it to prevent warpage then go back and tie your stiches together.

Also, I was able to get the filler pieces installed in two pieces per side. I cut the strips long and then cut a few 2" x 4" 's. I placed the 2" x 4" 's between the floor of the shop and the bottom of the wheel well. I hammered the wood to get them as vertical as possible. This holds the filler strips tight to the bottom and helps correct the high / low situation of the two well halves. You can slide the filler strips around as needed and use a rubber mallet to form and tack the upper corners.






Tom

[rpmrich]

i sprayed the inside of the wheel well with undercoating untill it covered the welds

[attachment deleted by admin]

[rpmrich]

here's one of the inside

[attachment deleted by admin]

[rharveysr]

I am going to run out on a thin limb here....Cant the filler strips be tacked between the wheel well halves instead of welding them on the bottem or inside??? 
Or...what would be the another option so that the inside of the wheel well looks like it came from the factory ...nice and fat?


Thanks
Rick

[19swinger70]

you could butt weld them in, but it's going to require more cutting/trimmiing/ fitting work. bending the contour to fit in between the halves might be pretty tedious, but if your good at sheet metal work, im sure you could do it. 

[b569rr]

you could butt weld them in, but it's going to require more cutting/trimmiing/ fitting work. bending the contour to fit in between the halves might be pretty tedious, but if your good at sheet metal work, im sure you could do it. 

That could be done by using the method I outlined above. After you jamb the filler in place,just put some scribe marks on the filler and cut it. That is alot of work that I didn't want to do.

Tom

[mopowers]

When you lap the filler pieces in, do they rust because they are bare metal.  Or does the polyurethane seam sealer seal the rust out?

[dustertogo]

 just spray them with weldthrough primer before welding them in and rust shouldn't be a problem.

[Halfaed]

Then after you have it all done, spray it with epoxy primer and paint it!

[70_440_Swinger]

I'm sure that will be fine. But I prefer to weld all of it. I like to have the weld be 99% of the sealer. Stitch weld it to prevent warpage then go back and tie your stiches together.

Also, I was able to get the filler pieces installed in two pieces per side. I cut the strips long and then cut a few 2" x 4" 's. I placed the 2" x 4" 's between the floor of the shop and the bottom of the wheel well. I hammered the wood to get them as vertical as possible. This holds the filler strips tight to the bottom and helps correct the high / low situation of the two well halves. You can slide the filler strips around as needed and use a rubber mallet to form and tack the upper corners.


Tom

That's a real clean looking job Tom. Wish you had done my tubs...

Looks like Stevie Wonder welded mine...

[mopowers]

Hey Tom, I picked up some .023 wire and wow it makes such a difference.  I'm not even that good, but I notice it.  I'll throw up some pictures when I'm done. 

[Rate]

Damn that's some clean welding >_> I can barely even go in a straight line

[b569rr]

Stevie Wonder. I don't care who you are, now that's funny.

Just make sure the metal is absolutley clean. Just a little contmaination will ruin your job.  And of course, stay away from inner shield.

Thanks guys. I do use the .030 when welding structural items. I post some chrome moly tig welds when ever my wife lets me start that project.

Tom

[70_440_Swinger]

And of course, stay away from inner shield.

Tom

By that do you mean Flux-core wire? Cause that's what I was using....

[b569rr]

And of course, stay away from inner shield.

Tom

By that do you mean Flux-core wire? Cause that's what I was using....

You can use it, but the home use inner shield tends to spatter a little more and fills the parent metal with contaminants. It is mainly used on structural steel (iron workers) where shielding gas isn't practical; welding with air movement like a breeze and pushing alot of wire.

Tom

[mopowers]

I finished up my minitubs this last weekend.  I will post some pictures in a bit.  They aren't as nice looking as your Tom, but not too bad for my first try.

[mopowers]

[70_440_Swinger]

Looks pretty good to me! Nice job!

[b569rr]

Yeah you did a great job. Keep it up.

Tom

[Small Block]

You boys see that hat Toms a wearin? What trade are you in Tom? Go ahead and tell em. Looks like it ought to.

[b569rr]

The hickory shirt and cap gave me away. I am a  Steamfitter by trade. We weld pipe of all sizes and metal types. Kind of like an Iron Worker with a twist.  Welding pipe is easy. This sheet metal thing is a pain in the butt. 

Tom

[fourspeed]

I finished up my minitubs this last weekend.  I will post some pictures in a bit.  They aren't as nice looking as your Tom, but not too bad for my first try.

Looks decent to me, man.