Friday, December 24, 2010

Some time off...

Well, Merry Christmas everyone.  I had to do the family thing for a few days and make the trek to lovely Bellevue, Iowa to spend the holidays with my wife’s family.  It is nice to have a break for a few days, but I do miss being in the shop.

I did get a chance to make some progress on the gas tank.  I have is pretty much finished up with the exception of a little bit of welding and getting the inside coated with a gas tank lining.  

I like to get the tank lined for several reasons.  First off, I do not trust the capability of my welds in keeping the gas from leaking.  Also, the lining aides in preventing the inside of the tank from rusting.  I have used several different types of tanking lining that are available from companies such as Eastwood with good success but the one thing that has bothered me with the DIY versions is the smell of the chemical concoction.  So, the last several tanks I have built, I have found that local radiator shops are more than capable and usually more than willing to perform this service for not much more that it cost to buy the stuff over the interwebs.

When it is all done, I want a tank that has a factory look to it instead a drab plain box that happens to hold gas.  The easiest way to do this is to add some raised beads to it.  Before I started to take everything together, I went ahead and added some beads to the sides and bottom since that is really anyone will ever see once it is bolted in.  This also helps control the warpage that is inevitable from when I go weld the perimeter.  I cheated and used a Pullmax with a 1/4" beading die.  I realize than not everyone one of these in their garage, but the same thing can be accomplished on a hand operated bead roller or even with a simple set of hammer dies. 

I am actually contemplating making a set of hammer dies.  I have had several occasions in which I have been unable to fit the piece that I was working on in the Pullmax.  I am thinking of taking two pieces of bar stock and separating them by 3/8" for the female die.  The male die could be made from a piece of 1/4 round stock with a piece of bar stock welded perpendicularly for a place to hammer on.  If you wanted to get real crazy, you could casenite the dies and polish them.

Well, at this point I have to apologize, I thought I brought my camera along with me to download the most recent pictures.  Not the case.  It is 9 hours away sitting on the work bench.  So I guess I will just have to wait until I get back home to finish the post on the gas tank.

Anyway, hope everyone has a Merry Christmas and a safe holiday.

Monday, December 20, 2010

Wrapping gifts....

Around this time of the year, it is so difficult to find time in between all of the holiday and family stuff.  Sorry I haven't posted anything.

Anyway, the next step for the gas tank is to make the perimeter.  I do not like to simiply make each individual side and then weld them all together.  The problem that arises is that you end up with a lot of weld in an area of the sheet metal that is not stiffened by an edge or lip.  This can lead to warpage and leakage.  Also, this type of joint is not very strong and vibration resistant either.  So my solution is to use one piece and wrap it around the sides. 

Since this particular tank has rounded corners, I have to make the wrap follow.  I started by cutting a piece of sheet metal the width I wanted for the tank and as long as the piece that I had.  Unfortunately, I did not have a piece long enough to wrap complete around, so I will have to do it in two pieces.  I picked a point on the tank that I felt comfortable to have a weld and this will be my starting point for my measuring.  I did not want to see any weld of joint when the tank was installed, so I decided to make the starting point on the front where it would be hidden by the cab.  On the side pieces, I measured back to the first corner where the corner started and then wrapped the tape measure around the corner to where that same radius ended.  I transferred those measurements to my wrap.

I then had to figure out how I was going to bend the corner.  I thought about using a break and stepping though the corner but that would yield a bunch of unsightly break lines.  I couldn't live with that, so, I can up with this....

I "built" what you could call a temporary corner break...I guess.  What ever you want to call it, I worked great.  I started with a piece of tubing that I found that was slightly smaller radius than the corner.  I screwed two pieces of wood to table about an 1/8" wider than the part I was bending.  This is to help line the part up to keep the bend perpendicular to the edge.  I then used some more wood to clamp the tubing down.  Once everything was in place and clamped down tightly, I bent the piece around the tube slowly just using hand power.  You can help persuade the part with a hammer but take care not to put hammer marks in the part.  I usually use a piece of wood in between the hammer and the part to help transfer the force over a wider area than that of the hammer face. 

I continued with the measuring and bending until I ran out of metal.  Since I had to do this in two pieces and I did not want to have to contend with a bunch of warpage, I bent a 1/2" lip on the start and end of the tank wrap.

On a side note, a project like this make you realize that you will NEVER have enough clamps.

Thursday, December 16, 2010

Ugly to usable....

Admittedly, the previous post had some pretty ugly pictures.   You might be wondering where I am going with this and why I look like a hack.  Well, be patient, damn it!  This stuff takes time and you can not be in a hurry.

So, continuing with the tank, you can only work the material around the form so long until you run into problems.   The issues I encounter is the particle board doesn't make a good form, it breaks easily.  So...out comes the hammer and dolly.  The tricky part of this entire project is the corners.  Once you get a rough shape stretched or pulled over the fragile form, you have to shrink the the material to achieve the desired shape.  This might seem counter productive to first stretch then shrink, but hopefully it becomes clear when you do it.  Anyway with a bit or persuasion, you can get it to look like this....

Admittedly, that is not too awfully impressive.  You can see somewhat in the picture how you "gain" material in the corner.  This extra material has to be trimmed away.  Trust me, this makes things sooo much easier to work with.  After some trimming and further hammer and dolly work, about 5-10 minutes worth, you can get something that looks like this.....

and then, some thing like this....

Bam! Now, make another side.  Be sure to make it a mirror copy of the first one.  Also make sure you router mirror sides of your forms.  My failure to do that had some impact on why I cracked my forms.

Wednesday, December 15, 2010

The current projects...

So, I have been referred to by friends as having A.D.D.  For those not familiar with this condition it is a disorder that.....ohh look at that, it's snowing!  Wait, what was I talking about....oh yeah.  Anyway, I tend to have quite a few projects going on at once.  Usually, I am working on three or four projects at the same time and jump back and forth between them when I get bored. 

One of the projects currently is a gas tank for a '40 ford truck that I am working on.  This truck started from a cab that I traded for a set of headers I built about a year ago.  I'll cover more on both of these in the future, I promise.  For the tank, I wanted it as large as I could make to fill in behind the passenger side of the cab in front of the rear end.  I took some measurements and made a quick and simple solidworks drawing.

It may be a bit hard to see from the drawing, but my plan is to create a 90 degree lip on the each side directed out and then wrap the top, front, bottom and back around. Where the wrap and the sides meet, I'll tig weld them together. 

I transferred the measurement to a piece of 3/4" particle board and cut two piece to use as forms for the sides.  I didn't want the lip on the sides to have a sharp bend, plus it would be difficult to manage the corners, so I opted to take a router and radius one side of the forms. 

Once I had the forms ready, I cut the sides out of 18ga.  I used 18ga primarily because that is the stock I had in inventory.  20ga is much easier to work with but 18ga will hold the shape much better.  I do not work with anything less than 20ga just because I find it difficult to weld.  I added about 5/8" extra material around all edges from the forms I cut.

In order to prevent the side from deforming as I hammer the lip, I sandwich the side between the two forms.  I started to hammer the at the corners.  This is because in order to get a nice clean radius corner, the material has to be stretched.  I do not want to simple beat the corner down but I want to pull and stretch it over the form.  This pulling is done with your hammer strokes.  I do not hit with the hammer straight up and down but with glazing blows in the direction that I want the material to go.  Once the corner has begun to take shape a move onto to the straight sections.  You want to work the edges down with several passes.  Each time you hit the metal, it is stretching it.  Stretching is what we want in the corners, not on the straights.  Here are some pics of what i am talking about....

Tuesday, December 14, 2010

So, you may be wondering what is Vintage Metalworks...

Well, let me tell you.  I wouldn't go as far to call myself a metal man, much to the likes of Fay Butler and Ron Covell or even the Marcel's, but I do dabble in sheetmetal fabrication as well as other metal working techniques.  I also have a love for everything vintage, primarly, vintage automobiles.  So, do you understand the name?  Good.

The reason I wanted to start this blog is to hopefully help others looking for information.  When I started, there was not many places that I could turn for information and techniques and had to learn much or what I know from trail and error.  So, hopefully you'll find this spot interesting, helpful and maybe a bit entertaining.