Proper concrete for footings and distortion correction

Fabrication

I'm currently working on a rail that is to be installed in a pre cored retaining wall with 3" dia. and 8" depth for posting. The stancheons are 1" sq. tube 1/8" wall.I generally use mechanical fasteners but since the holes were there and on fairly accurate 6' centres I decided totake advantage of them....... Question: what is the best mortar/concrete to use and should the metal (aside from being powder coated) be treated with some type of coating for longevity.
The bottom of the stancheons are open and the tops where they meet the top rail are %100 welded. One reason I'm concerned is some rail on an apartment I occasionaly repair which is set in sometype of dense dark grey concrete like (?)fixative has horrid corrosion, and although the welding on these is extremely shoddy ( ie. incomplete fusion, holes in welds, excessive porosity allowing water to get in from the top)I wonder if the installation into the fixative was suspect? These existing rails are no older than 30 years old.

Since I'm on a wordy tangent I have two other querries,

One is that of distortion correction or prevention techniques or literature that aren't directed towards ship builders and the like ( has anyone ever used Wagners 3 chock straightener?)

Two, possibly the unanswerable one that of bidding or pricing standards for non-commercial architectural metal?

Pointing me in any direction for any of these would be greatly appreciated.

Thank you


Canaday Designs's picture

Hi J4,

Hi J4, and welcome,
First off, pour-stone is the product I use for cored aplication, and it sounds like the rusted rail your talking about is because of poor fabrication and finishing of the railing.

as to the straitener, it works great just take it slow or you end up with a dog leg

and pricing, ha ha ha, good luck

#1 - your only as good as your last job
#2 - you will learn when it costs you
#3 - when you figure out the answer to bidding let me know

the bidding subject is a bit tricky, every geological area is difforant as to the market and demand, also every smith is difforan as to how much there end product is WORTH.
I for one would be more than happy to share money isues after I have seen your work. Not to be rude, but the product always comes first.

Matt


J4's picture

Thanx Matt and Enrique

Both very good answers on all points. And Matt, Ha Ha on pricing is exactly what I expected. It's definitely a tough one. I've often felt as if I were charging to much and to little at the same time.

Further more, you are both brilliant artisans and I learn much from viewing your works. I will try to get some JPEG's
up as soon as I buy an airporter for my Mac.

As far as geography goes I am in Seattle
Thank you again.


webminster's picture

I use roofing tar to coat

I use roofing tar to coat the part of the metal which will be inside the concrete. Apply liberally and wrap it with plastic until installation. The reason for the plastic is because the roofing tar does not dry very well, and since you will be applying a thick coat, it likely not to dry until months later.

My understanding from talking with an architect is that the tar prevents the acidity from the concrete from passivation to the steel.


alex b.'s picture

i concure

Alex b. here in California, i don't know were you are, most contractors use "pour stone","rockite", which are name brands for non-shrink, it actually expands about 15% to fill in all the cracks, self leveling, sets in 15 minutes type mixture that comes in 10lb box's or 5 gallon buckets. King Architectural Metals {kingmetals.com} has the rockite and manufacture says does not have any additives that promote rust. $41.95 per bucket and they ship and will send you a free catalog. {i don't work for them, just use their stuff.}
When i install steel this way i always seal the bottom with primer and paint, if project is to be painted.
if powdercoat, then it is already coated.
if patina clear coat on part installed in the set.
i have used the "tar" as in "henrys" roof emulsion on the bottom of red wood 4x4 post for wood jobs, but have't used it on steel, but this does sound like it would work there also.
hope that helps.
as far as bibbing---------wow, i trip on that all the time.
from talking to clients, other contractors, and my wife, and even God. when a job is a straight forward time and material job, {meaning something basic like repetitive panels, or basic gates, or what ever it is you do, and all it will take is cut, weld, finish, install, i add all that time and material up, add on my profit margin and that is it. a very good piece of advice i got from someone, some were said, do not bid against some else or compromise your minimum needs financially to do a job. you will only regret it. bid it on what you must have and stick to it. i always tell the client that it is not my money any way, it is my wifes and my kids,and my churches. if i have to come down a little it is only in that "profit" zone and then it still is only a little.
one more,{i wonder if there is a message limit on these chat sessions?} as far as the "custom" jobs go. my experience has been bid as before,but also add on for that extra time, which is always more then you think it will be. extra time for me is the drawings, and re-drawings,the measuring and remeasuring, the changes and extra finishing touches that only you know about but must do so you can sleep at night and not worry that someone will see it later. the change in patina formulas cause it didn't come out right. the dreaded unknowns. and last is the fact that they want you to share a part of your self that is personal, your talent and heart for better then average, and better then they can get at "home depot". most clients who want "custom" know and expect this, if it is not special, they will let you know, and if it is, they will let you know that as well.
good luck and God bless you and yours.


bebo's picture

distortion control and correction

There is a book by a canadian fabricator by the name of John P. Stewart that is a tremendous resource for distortion control in steel weldments. Also checkout a guy who calls himself lotechman. I beleive he has a webpage on geocities. It has some great pics and descriptions of the causes, prevention, and cures of distortion.


hjnwt's picture

Proper footings for stancheons

J4,

I would set anchor bolts if possible. Use Epoxy Grout to develop the strength. Most of the Epoxy Grouts develop 60K
PSI. Weld a base plate on to the bottom of the post with holes for the anchor bolts. Shim them up to 1" and place 4 nails on 90 degrees that can be removed latter to promote positive drainage. I would also drill two small weep holes just above the base plate into the tubing to allow any water that gets into the tube to relieve itself.

Hope this helps.


Stephen Fitz-Gerald's picture

railing notes

Stephen Fitz-Gerald
I agree with hjnwt,weep holes are a must...
In addition I make sure whatever goes in the ground is solid metal ,NOT tubing. When I make a rail with 1 inch square tubing posts,I weld 8 or so inches of 3/4 round bar to the bottom of the tube with at least 8 inches up inside the tube as well. This is a good stiffener and means you get a solid bar in the ground.
Also I personally don't do any installs. I tell the client upfront that he must make a separate contract with a good contractor ,and then I recommend him mine.Ninety percent of the time they take my advice. I've been working with a fantastic and reasonable contractor doing my installations for 20 years.He has the PORTABLE TOOLS, the LIABILITY INSURANCE, and the CONTRACTORS LICENSE,none of which I have. I am always present for the install and WORK FOR FREE on that day,but shoulder none of the official responsibility.This arrangement has served me well over the years.
Bidding a job is often a sticky wicket.My technique is thus;
Since I DESIGN as well as FABRICATE,and nearly everything I make is site specific,I have a base price(or minimum) of $275 per lineal foot for the simplest of designs. Obviously curves or stairways are more difficult to execute so those are an added charge.My most expensive is about $500 per lineal foot (Art Nouveau stuff):
http://www.sfitzgeraldfineart.com/custom-gates/
(page two-The Guimard Gate)
Your question about warpage has two solutions;
First you clamp the shit out of everything you weld ON YOUR FLAT THICK JIG TABLE,especially if it has uneven spacing of the welds.Clamps are cheap,there is no such thing as "over clamping". Also I have consistently gone to thicker and thicker railing members over the years,cap rails,newels etc. to avoid heat warpage from welding.It's just easier and there's less chance it'll go haywire on you if it's thick and heavy material. This is of course even more true of stainless and other non ferrous metals...
I hope these logistics help.
But we're all different and have different strengths and weaknesses. These contrivances help me but that doesn't mean they would work for you. So take from this advice what fits and is helpful and discard the rest...In the end you want to feature your strengths and sublimate your weaknesses. How you do that is a personal thing...