Big job questions

[FieryFurnace]

I have a chance at a large scale job in Nashville. (To me it is large scale comparing it to what I have done in the past.) I do not believe the job is out of my reach, but it will certainly be a challenge.

Here it is:

A client wants a table, 10' long, aprroximately 30 inches deep, and 34 inches tall.

My first question and the only one for now, is this. I am not providing the table top. The client wants a forged base for a 1 1/2" stone slab. How heavy is a 1 1/2"x32"x10' stone slab going to be???
My guess would be 150-200 LBS but maybe that is low.

The idea the client has is fairly simple...Legs straight up with a few "fleur-di-lis", a lower level of the table that has 3-4 inches of clearance from the ground and some X-braces. We are looking at a lot of mortise and tennon joints. I'll probably change the X-braces to long crossed scrolls using collars, or chord rap over mig.

I've got to get drawing a scaled down design and send it to the client.

I'm excited! It seems pretty big to me. My client got his "assistant" to email me and asked me for a "bid." Sounds like I got competition! LOL I'm a bit nervous! LOL

Thanks.....

Thoughts????

[ciladog]

Different stone has different densities so some of this is dependent on the type of stone the top is made from. If the top were made of granit (density is about 168 lbs/cu.ft) the top would weigh about 560 lbs. at the dimentions you mentioned.

[pkrankow]

http://www.avlandesign.com/density_stone.htm

http://www.austinpowder.com/blastersguide/blasterstools/rock-densities.htm

Thank you Ciladog, 560lbs of top agrees with what I came up with.

A36 has a strength of 36,000 psi, so 1 inch square stock can resist 36,000lbs under ideal circumstances. This means that if you have the table built to aesthetics, from solid steel, I doubt there will be a strength issue. You issue will be more with flexibility of the steel and having wobble from springiness.

Phil

[bigfootnampa]

Yeah Dave I am showing about 625 pounds for granite if they make it solid. Sometimes they just make the edges 1 1/2" and maybe a stringer in the middle That way would probably knock off 200 pounds. Even hardwood would be over 200 pounds for that size.

Even if you are the only bidder they still want a bid so that they know what to budget. I wouldn't worry about competition... your tendency is to underbid so if you lose the deal I am gonna say that it probably would not have been good for you anyway.

[FieryFurnace]

I looked up limestone and I got about the same as granit! eeeesh! That's a lot of weight!

Oh another question, and this figures into pricing here.

This is an exterior porch piece. Is powder coating going to be the best option, or maybe just an auto-grade clear-coat? I'd like to go clear. Can you do clear in powder coating? This is not the bathroom tishue holder and Krylon clear isn't going to cut it. Anyway, thoughts on what the best coating would be would be great.

I noticed a website link on the email the guy sent. Wew! These people have a big company with four branches, one in Los Angeles, Monterey, Nashville, and New York. That made me feel a LOT better! LOL

I'm going to do some serious stock, shop supply, finish, time, and delivery figuring and try to price right. More than likely I'll underbid again, but I hope to shoot closer to the mark.

Thanks for your help!

[jake pogrebinsky]

Dave,good for you,very happy to hear this,and i think that the guy knows what he's doing when he chose you,you're an accomodating fellow and he figured that he'll get what he wants by dealing with you.
Don't underbid,if you can help it.Putting the price on your work is...Just that very thing.Bidding high will mean that you've every reason to believe that you'll do a superlative job.THAT's why you're higher than someone else,you'll do a BETTER job.

The weight is an issue only in the footprint dept.You may do a quick calc.of the psi exerted on what flooring,et c.Softwood decking on porch may mean having to spread the load a bit more.

Phil brought up a very wise point-wobble,or any form of flex or un-steadiness.Steel is pretty elastic(i remember how surprisingly soft the 16" by 8" I-beam turned out to be,surpriesed me,anyway).But the project seems straightforward enough,and you should be fine just using your common sense.

The VERY best of luck with it!

[bigfootnampa]

Clear coat powder coating can be done but the clear coats are universally less durable than opaque coats. For a project like this I think you'd be better off with a cold galvanizing primer and something like hammerite for a finish. You can work such a finish out to appear remarkably like the clear coat on forged metal would and yet you get much better durability. Here's a link to some of the cold galvanizing primer (I've no idea if this is a very good example Dave, just picked at random to show what I am talking about): http://www.clearcoproducts.com/cold_galvanize_sprays.html Dave I often use hammerite or similar textured spray can finishes and mix them up a little to simulate blacksmith finishes and for a piece of work this size it wouldn't be too bad an option. I know that it seems chintzy but I do top quality finishes this way sometimes. The paint is more expensive this way but clean-up is a breeze. The cans won't spray as smooth as my Accuspray HVLP rig but for a textured finish anyway there is no loss in quality. Waste and overstock is also minimized.

[FieryFurnace]

Thanks for the continued helpful input! Answered alot of questions already.

Ok design! Frst off we are discussing wobble. That's obviously a concern.
So on those lines I have some questions. I'm not used to dealing with large stock and abilities.

If I use 1" square for the legs, could I inset 1/2x2 flat bar to a depth of 1/2" into the leg so that I can rivet the two together, flush? Or would that decrease the overall strength too much requiring that I upsize to 1 1/2" sqare or so?

I would rather over-engineer than the other way around.
I am thinking about adding C-scrolls in the upper corners of the table to help prevent wobble. Is this a sutable solution?

The footprint issue is a great addition to the conversation thus far. I hadn't thought about that. I was already planning on upsetting the bottom of the legs anyway, which will obviously help. However, it might be wise to mount some plates under the legs.

I will be calling the client tomorrow to get some more information.
So far:
The type of stone table top.
I'm going to clarify some conflicting measurements he gave me.
The type of flooring this will be sitting on.

Anything else I should be asking?

I appreciate the link to the paint and will keep that filed away. I've got to figure out something for pricing purposes.

I really appreciate you folks pitching in and taking your time up to help me!

[Glenn]

Powdercoat chips and lets in moisture and the whole thing starts to pop off exposing the rust. Use paint, it can be repaired if chipped. Rust-o-lum and others have a hammered finish paint. WARNING it is intended for horizontal application only. Angle iron must be painted in 4 different applications, each side being horizontal during the application.

If you send the client a drawing of what you intend to build, plan on YOUR drawing going to the other bidders. At some point one of the other bidders will build YOUR project at a cheaper price, because they do not have to do any design work. Lap top computers are wonderful for a presentation as you take them (and your designs) back home with you.

Think heavy on the legs, such as 2 inch, which will allow you to do many more design features. Use your blacksmithing to make scrolls and infill scrolls to brace and cross-brace the table. Decorative elements, a drawer under the table, etc will add value to the project. Look at some of the decorative elements that Hofi has produced for reference.

Make the metal support strong enough to hold not only the 560 pound table top, but add on another 1000 pounds of load. Remember that during the party there may be several dancing girls standing, jumping, and dancing on the table.

As to the footprint, you can rework larger leg stock into many different elements that have a much larger footprint. Think claw foot table legs, etc, or split the leg into two or four sections, each having a much larger footprint than just the end of the parent stock.

When you bid, include a clause that your bid is based on today's steel prices, labor prices, and today's cost of materials. Any price increases will be reflected in the final price. Did you charge for shipping this table frame or are you going to rent a truck and deliver it for free? Did you charge for properly finishing the table frame? Did you figure in the hoist needed to lift the thing or the hired help needed to assist you? Did you add 20 percent (or more) to the bid to cover any thing you may have overlooked? There is nothing wrong with making a high bid and upon delivery presenting him with a check refunding any difference between your estimated bid and the actual amount of funds used to make the project.

[John B]

To answer your question

If I use 1" square for the legs, could I inset 1/2x2 flat bar to a depth of 1/2" into the leg so that I can rivet the two together, flush? Or would that decrease the overall strength too much requiring that I upsize to 1 1/2" sqare or so?

Not quite sure what you mean by the rivet the two together flush, I am assuming you intend to make it look like one continuous piece passing through the leg.

I would suggest slitting and drifting the leg to the size of the pass through and then pin/rivet the pass through in situ you can then make a feature of the joint, and you will also have better rigidity and strength than using two seperate pieces butted together, and with two rivets through a relatively thin leg, a potential weak spot.

I would aslo consider upping the leg sizes from an aesthetic point as 1" square on a 10 foot table seems a little spindly.

Don't know if this helps or not, Just a thought, Good luck with the project and don't sell yourself short.

Another alternative if you are using forge textured bar for your 1/2" x 2" would be to use a halving joint with a central rivet and/or crossed collar to attach it securely

[Randy]

Everyone is right on the mark. Only thing I would add is that if on an outside porch that probably means it's not a level floor. It slopes away from the house. So, do you need levelers on the feet or how are they/you going to compensate for the sloped floor? Details, details.

[Francis Trez Cole]

I designed one for a customer once the base ended up weighed more than the top. The big thing is strength you are on the right track. You will have to check the porch can it hold the weight of table and base. I would have them pay for the metal up front and charge them by the hour to build it. Heating 2" solid stock will take and appropriate amount of fuel and time. You may want some type of rail and pulley system to help in moving the hot metal around from forge to anvil or power hammer rather than muscling it around . you will have to add a delivery charge or calculate freight and then moving around the completed base from truck to porch, There are logistics.

[FieryFurnace]

Ok sorry I left out some important information.

The table will be built in three separate units. The drawing the client sent me says that each unit is 48 inches long but he told me over the phone that he wants a 10 foot table. That's where I have the conflicting measurements.
However, the table will be built by section. This REALLY helps me out, because I'll be dealing with shorter stock lengths in the shop and a lighter section to move.

Each section has four legs front and back. This will help with weight distribution and overall stability. The inner legs that but against the next section will be half the width of the outer legs so that when the piece is put together the size matches.

This is the drawing the client sent me.This is one section. The inner legs are simply bars to mount the X-brace to. The center of the X-brace will have a fleur-d-lis mounted on a fleurette. (That should be a blast! LOL)


(The above drawing was not done to scale. The two X-brace systems are 17" wide and there is 14" of space between them.)
I am changing the X-brace into a scroll system.
I really like the idea of the pass through Mr. John. To achieve what I was referring to you would heat the 1" stock where the 2" crosses it, ad hammer a cold 2" bar into the material until it was flat across the surface! Pass through would look better and would retain the material thickness.

I would most likely deliver the piece myself. The client is about 2 hours away and I have a truck and trailer that I can deliver it on. I would think two people would be able to handle each section without too much difficulty.
The point about the porch slope is a valid one. Thanks for bringing that up.

I also like the idea of an in-person lap-top presentation. We go to Nashville occasionaly, and I could line up a trip around when the client is available.

"bout time to call him!

Thanks!

[pkrankow]

One option is to build the ends, and then simply join the ends together with tubular steel, and bolted flanges.

Triangles will stiffen up your sections and reduce wobble. Straight sided triangles will be more rigid than scroll work set to form triangles, but the scroll work will add more visual potential.

Will this table be set against a wall or in the middle of a floor, or used as a serving bar? If it is against the wall, then bracing goes against the wall. With a serving bar that back should be open to allow storage, and the front should be opaque, so the bracing goes into the embellishments. If it is a free standing table it is viewable from all sides, so the bracing has to be decorative.

Good points about the strength of soft wood flooring. Nothing worse than having the floor damaged by the table. You can hide levelers in feet that slide along the leg so the levelers are not plainly visible. Having all feet adjustable is best, especially since you seem to have more than 4 feet already in the design. Having more feet is better for the flooring material. Simply add up the expected weight of the table materials and load rating of the table (several dancing girls) and divide by the total are of contact for all the feet, then compare to a grain compression pressure for wood. Apply a useful safety factor, no need to be designing close to the edge on this.

When I stated 1 inch square earlier, that was a strength example. The single piece of material is more than enough to support the weight given. You can probably use much lighter material and have a successful table, but you need to do the aesthetic design then select the stock you wish to use. Tube stock, or channel may be the best choice for straight structural pieces because it looks big, yet is mostly air space so it is lighter. It also distributes material far from the bending axis making it stiff.

I am sure you will have a good design.

Phil

[pkrankow]

http://www.woodworkw...-strengths.html

spruce is about 400psi for compression perpendicular to the grain. This means that if you have 4000# of table and dancing girls you need at least 8 square inches of floor contact to prevent floor damage. You probably want to double or quadruple that number for a practical safety factor.

Phil

I made a math error, 4000#/400psi = 10 inch^2

Phil

[arftist]

Just my personal preference, but I would use only solid stock for a stone table. Chanel is OK but not tube. Granted the tube would be strong enough given so many legs, I just don't like it when mixed with stone. Stone is massive and solid, it's support should be as well.

[Francis Trez Cole]

choice of material and style is the key. What I have seen of your work it is traditional and is that the clients expatiation tube and channel would be more modern cant wait to see what you come up with for the final piece.

[FieryFurnace]

BIG FAT HAIRY DUH!!!!!!!! LIGHT BULB!

Look back at the drawing! The table doesn't have eight legs it only has four. The table is actually only 17 inches deep so the X-braces with the Fleur-d-lis and Fleurette are the ends of the table. I talked to him and he mentioned it being 17 inches deep. So we are back to four legs. The drawing is supposed to be three dimensional.

I agree that solid is the way to go here. I am a traditionalist and alwasy prefer solid over pipe.

The table will be up against a wall, so I'm ony dealing with the two ends and the front needing to be the "beautiful" parts.
The client is undecided as to wether he wants 12' as the total length or 10', and he is also undecided as to whether he wants each unit to be independant or not. He is supposed to get back with me on that tomorrow. All of that effects design so I'm at a halt as to what I can do.

Table top weight is reduced as well seeing the decreased table top size........that makes things a little easier.

Oh for weight figuring purposes.....how much does the average dancing girl weigh? LOL

[bigfootnampa]

In today's world dancing girls are surprisingly heavy! Though not so heavy as housewives as a general rule. You'd really be best off to figure on Reubenesque dancing girls which are likely to run up to about 180 pounds. Though on occasion one might be encountered which exceeds this weight I would think that you'd be safe to use it for design purposes.

[Glenn]

Think of the dancing girls as active loading, not static loading (grin).

[FieryFurnace]

you guys are nuts! LOL Back on topic!

[Frosty]

Congrats Dave! I only have a couple suggestions.

Has the customer specified how the top is to be mounted? I did a stone topped end table for my bone doc's office a couple years ago. I made a flat stock rim that morticed to the top of the legs and ran all the way around as the contact for the stone top and glued felt to it so it wouldn't scar the polished limestone and wouldn't let it slide easily. It's easy enough to move but someone bumping it with their leg won't budge it.

Price it higher than you think it's worth, it'll be worth it when you're done. If the customer wants to counter offer negotiate. I don't know how many guys under value their work. Believe it or not folk will buy expensive hand made much sooner than bargain hand made work.

Ask the customer about finishes. Paint is traditional for exterior iron work and is much MUCH lower maint than oiled or waxed. I'm not a fan of powder coating but it IS getting better every time I look.

Proportioning the legs is important and I'm thinking 1" sq. is just too thin to look well though with the right cross bracing it's plenty strong and stable enough. Crossing "S" scroll bracing will look nicer and be as strong as straight "X" braces but it's the customer's call.

Good for you Dave, really good.

Frosty the Lucky.

[Frosty]

you guys are nuts! LOL Back on topic!

You're right Dave, modern dancing girls often fit more into the static load category, especially the heavy ones.

Of course a nice brass pole to the ceiling would make a handy reinforcement.

Frosty the Lucky.

[FieryFurnace]

I'm drawing the line and forging a brass pole!

Ok seriously! I talked to the client yesterday and he said he was going with "Alabama" stone or Limestone. I can't find anything on the "Alabama" stone. I suppose there is a different name or it. Limestone is 163 LBS/CF. Due to the missunderstanding with the drawing lay out the actual table top dimension will be 17 deep and 10 or 12 feet long. (Client is undecided on length as of yet.) At 17"x12' liimestone would b about 346.4 pounds.) He is not going with one solid piece so the slabs will be manageable.

The deck is concrete, so we are good on footprint weight. I didn't ask if there was a drain slant on the pad. I didn't want to bombard the guy with a zillion questions all at once and scare him off, and that does not affect overall design right now.
He is supposed to call me back today with final length and also if the sections will be independant or dependant. If the tables are dependant then the inside legs that will butt against the next section will be half of he width of the outer legs. Then when the sections are put together the inner legs will be the same width as the outer. I thought countersunk screws could be used to attach the inner legs together.

However if the client wants each section to be independant then all of the legs will be the same size. I can't draw the front view until I get a confirmation on length but I am working on the end view with the "Fleur-de-lis" on a "Fleurette." Which raises another question. I looked up "Fleurette" to see if there was a sort of "standard" design. All I got was a bunch of different flowers. So, what is a blacksmith's definition of a "Fleurette?" Is there a certain "Fleurette" that is particularly suitable to back a "Fleur-de-lis?"

That's the latest!

[David E.]

For Fleurette I would read "Rosette". If there are 3 separate sections your biggest problem is going to be locking them all together in an aesthetic way and maintaining stabilty and rigidity, as three stone slabs at different heights with gaps between will not look too good. I am sure you will find a solution, good luck.