Opinion wanted, corrosion protection,

[BHD]

NOTE: this work is for my self and my own project

I will be making some tower anchors here soon, that will have a concrete foot on them but the shank of the anchor will be 1" steel shaft, I do not have a place I can take them for hot dip galvanizing, (nor do I want to buy them for the expense factor)

the thoughts I have is to use a cold galvanizing compound on them, Probably do that regardless, (originally I was going to slip some heat shrink tubing on the shafts and shrink it down), but three days ago I found a bunch of used 1" shafting, the problem is on the machine that it was used on had a center bearing and they decided to cut the shaft in half and then weld a tube over it instead of taking the shaft lose from one end and sliding on the new bearing,

since I was planing on running a twin shaft in the first place, my current thought is to add a short section of shaft where ever I have to weld the shafts back together, staggering any splices,

OK that ends the possibility of using the heat shrink tubing, unless I go and buy new shaft,

so I was thinking of sliding a piece of sewer pipe, over the shaft, and after the anchor is in place fill that tube (in the ground) with a cement grout,

what IDEAS do you guys and gals have,

the anchors would be similar to the second one, in the picture, the unit with the double shafts,
http://www.ehresmannengineering.com/Anchor Shafts.jpg
set in to concrete similar to his one about to be poured,
http://www.qsl.net/zf2nt/guy_anchor.jpg
one with the concrete poured,
http://www.rr1.net/users/hwknoebel/anchor.jpg

 

[Renze]

I coat all the invisible parts of my machinery (underside of the manure spreader, spreading mills, the underside of my farm wagons, insides of the cover on the street sweep) with black varnish, a bitumen based coat, similar to car underbody coating.
IT bites itself into rust, and in salt environments it works better than galvanising. (in salt environments, the electrolytic current reverses the galvanising process)

The stuff is cheaper than paint and protects better. I spray it on, with the air compressor with a degreaser spray can. (not with the paint sprayer, the stuff is too sticky for it)

 

[Skyco]

Wow, that must be a heck of a tower to need two 1" shafts on each guy anchor Fill us in please

I'd cold gal them and then coat them with the bitumen/tar stuff. I definitely wouldn't grout them in a pipe unless the cold gal/bitumen was done as well.

http://www.densona.com/pdfs/DensoLiquidCoatings/DensoBitumenMastic.pdf

 

[jimgerken]

I've had good luck with cold galvanize spray paint. One thing: from the picture, the steel seems to leave the concrete and then travel through dirt to get to the final length above ground. I would reconsider this, making sure the steel does not touching any dirt (use more concrete). On the other hand, maybe I have misunderstood the picture.

 

[BHD]

Skyco
two 1" shafts on each guy anchor.

I doubt if it needs 2 1" shafts, there was no remanates of the original anchors, and originally it was nearly 3 times taller than I am wanting to go with it , so it would have made little difference any way.

two reasons on the twin shafts, one is if some type of failure would occur, hopefully one would remain, two if there was corrosion that it would be more than needed even if corrosion was sever, (on a guy tower, if one guy anchor goes so the tower will go, the smallest guy cable/wire is 1/2" that I have to reuse, I would think I could use other smaller cable/wire but if I have enough of the current wire I will probably use it, (the top wires were 7/8 on the original configuration),

the tower is approximate a 3 foot face on it,

currently the tower plan is for 80 to 100' in time it may support a 20kw wind turbine, currently looking at a 10kw unit,

have enough for 160 feet, but not going that height and have considered the possibly of two 80' towers with smaller 10kw turbines on them insted of one larger 20kw,

with a telescoping top on it for the turbine, (about 15 additional feet, telescoping one for blade clearance to the tower, and two I hope to have a "crow's nest" type platform at the top to if service is needed one can lower the turbine down work on safer and comfortable platform with a little room, then trying to do it hanging by a belt on a pole 100+ feet in the air, standing on screw in Foot pegs,

jimgerken
One thing: from the picture, the steel seems to leave the concrete and then travel through dirt to get to the final length above ground. I would reconsider this, making sure the steel does not touching any dirt (use more concrete). On the other hand, maybe I have misunderstood the picture.

this is why I was considering a plastic (sewer) pipe sleeve and grouting it full of cement sand grout, by do it with a plastic sleeve I use very little concrete to encompass them as normally re-bar in concrete is usually fairly sound even years and years later,

the bitumen based coat is a thought I had never considered, thank you Renze and Skyco

at one time and may still consider setting up two towers, one at 40' or so for a test strand for some turbine designs, and then the a larger one for long term use,

 

[firedog]

In addition, you might also consider a cathodic protection system, using what's know as a sacrifical anode that will corrode instead of the iron rods.
It's an idea I'm currently considering for the fence I am building. A simple cathodic system would use an aluminum anode (rod or scrap piece) buried in the soil near the anchor with a aluminum conductor (wire) attaching it to the steel or iron rod. Here's a link with additional info: Marpo

 

[Skyco]

I've had good luck with cold galvanize spray paint. One thing: from the picture, the steel seems to leave the concrete and then travel through dirt to get to the final length above ground. I would reconsider this, making sure the steel does not touching any dirt (use more concrete). On the other hand, maybe I have misunderstood the picture.

The norm in commercial towers is for the guy anchors to extend through dirt, of course they are hot dipped galvanized.

I gotta tell you BHD considering the scope of the project I'd sure look into commercially made tower rated guy anchors that are hot dipped.

 

[bx24]

BHD

Have you priced regular utility anchors? You should be able to get them fairly cheap from a supplier, or buy a telephone or power line crew pizza or doughnuts and they may set you up

Guy Anchors

 

[BHD]

Thank you for all the replies,

I may end up using a combination of all the above,

here is a link for a PDF, on tower anchor corrosion,

http://www.anchorguard.com/understanding.pdf

if pdfs are not good here are in a web page format,

Anchor Guard: Understanding and Preventing

Anchor Guard: Understanding and Preventing

Anchor Guard: Understanding and Preventing

Anchor Guard: Understanding and Preventing

Anchor Guard: Understanding and Preventing

Anchor Guard: Understanding and Preventing

Anchor Guard: Understanding and Preventing

when I priced some anchors early they were in the $150+ range and would need to be trucked in, not ups,
~~~~~~~~~~~~~~~~~

the unit similar to what I want to build, through Valmont industries,

Style A, Length A=10', 5 anchor holes, P/N 102305 Turnbuckle sizes 5/8" & 3/4", 56 lbs. $210.00

actuly the one closer in design, but looks to heaver than what I considering to build,

Style C, Length A=10', 7 anchor holes, Turnbuckle sizes 7/8" & 1", 175 lbs. p/n
105000 $650.00

[/quote]

 

[Redbug]

I would coat them with blackjack...roofing tar. You can buy it in 1 gallon size and larger for pretty cheap. Then, let them dry out in the sun a couple weeks before use.