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How to Build a Grain Bin--Main Rings and Ladder: An Illustrated Guide

Joy worked in construction for 7 years alongside her husband (25+ yrs. experience)—working on pole barns, grain bins, and barn repairs.

A Fully Erected Grain Bin With Hopper

This 18-foot diameter, 4,000 bushel bin is finished, and mounted on a hopper, ready for harvest time.

This 18-foot diameter, 4,000 bushel bin is finished, and mounted on a hopper, ready for harvest time.

Main Rings of Sheets--Overview

The lower sheets are installed one ring at a time, with strict attention giving to proper lapping. A sealant in a rubbery tape form, called mastic, is applied at each seam. Drift punches are used to help lift and align the sheets. An impact wrench and box end wrenches are used to tighten the bolts. As with the first ring, this is a two-person job, with the impact wrench operator inside the bin, and the other person outside, holding the bolt heads steady with the box end wrenches. This job requires strong wrists, good dexterity, and good mobility.

Each ring of sheets is completely bolted together, then the bolts are tightened before proceeding to the next ring.

If you have not seen the article showing how to put together the first ring, please refer to it for tips on sheet lapping, sealant application, drift punch use, and tightening of bolts at seams. We include only a refresher course here.

Tools and Equipment Needed for This Stage of Construction

  • Proper grain bin jacks--you must rent or buy these from a reputable grain bin tools source, or manufacture a set yourself if you're exceptionally handy with a welder
  • Alternate way to lift the bin, if desired--crane, boomtruck, or large forklift (forklift for small bins only!)
  • Lifting ring, large truck rim, or lifting halo
  • Lighting if working at night
  • Drift punches, medium length (10 inches at least)--1 minimum for each crew member
  • 9/16-inch box-end wrenches (2 at least), with long handles
  • High quality impact wrench, as you will give it a work-out
  • Hearing protection--preferably ear-muff or electronic type
  • Work gloves which allow for dexterity (optional)
  • Comfortable work boots with decent tread, hard toes optional
  • Work clothes which will not snag or allow you to get hurt easily
  • Vice grips, high quality
  • Slipjoint pliers (optional, but can be handy)
  • Tool pouch/apron, or coffee cans/small buckets for hardware (a small pouch is annoying as it must be refilled often, and is hard to reach into)
  • Mastic (a sealant for between sheets)--can be found using the search words: Single Bead Tape Roof Sealant Metal Sales
  • A way to block wind from swaying or sliding the bin during work (we often use a semi truck and trailer)
  • T-posts for driving in around the partially built bin during off-hours, or a suitable way to weigh the bin down at the peak (i.e. the boom of a boomtruck or crane)
  • Forklift, ATV, or another way to move the sheets and other materials on and off the jobsite
  • Storage building for bin components, if they must sit between building sessions

Work Conditions and Cautions

As with any phase of grain bin construction, great care must be taken each time the bin is lifted in preparation for the next ring. Winds and other weather conditions must be considered. If it is too breezy, cold, or hot, postpone lifting the bin. Instead, anchor it firmly, and play it safe. The rush to get a job completed is not worth anyone's life or body parts.

Adverse conditions lead to exhaustion, clumsiness, and mistakes. A cloudy mind and slow reaction times may prove hazardous to yourself and fellow crew members. Even if you are on a deadline, take short breaks for protein-based snacks, and stay hydrated. In very hot weather, consider supplementing with potassium, which may help you stay in balance and resist muscle fatigue.

Starting the Second Ring of Sheets

Before raising the bin to begin on ring #2, you must install the first section of the main ladder, if applicable. See below for how to do this step.

Scatter the appropriate number of sheets from the stack, facing them as much as possible the right way so getting them in position is simple.

Have all tools and hardware handy.

If there is a door in the side of your bin, naturally you'll have calculated from the instruction manual where it goes, so you know where to start. If there is no main door, only a manhole in the lid, start about halfway around the bin opposite of this, centering your first sheet on a previous seam above it.

Impact Wrench Tips and Notes

What to Aim For

With a high quality electric impact, you should be able to tighten 3 nuts per second or more during re-assembly. Have a person on the outside with 2 box-end wrenches holding the heads of the bolts as you tighten the nuts. 5/16 nuts should only be tightened around 22 foot pounds, and I normally go a little more. 3/8 nuts should be tightened around 38 to 42 foot pounds. On a 48' diameter bin, the black impact socket will often turn cherry red by the time a ring is completely tightened. Remember, tighten the nuts, not the bolts. You may need good gloves and rags to hold on to the impact after a while, as the gun will get extremely hot.

Brands

Jepson impacts (now out of business), are my favorite brand. Their impact wrenches out-perform any other gun on the market. They do not seriously over-heat, and they take the abuse.

If you cannot find a Jepson, a DeWalt or Milwaukee are your second best options.

Electric vs. Pneumatic

On a big bin, both types of impact guns give problems. If you are working fast, a pneumatic wrench will get very cold or freeze up. This is extremely uncomfortable to hold, even if the gun still works.

Also on a big project, an electric impact will overheat and possibly fry. You may continue to use a hot gun by wearing gloves and wrapping the handle in rags so you don't burn your hands.

There is no good solution to these problems if you want to work fast.

Additionally, a pneumatic gun will not keep up with the demands of an experienced builder even with a decently big air compressor. The compressor will need to refill frequently, forcing the crew member to stand idle waiting for it.

Hardware Tightening Specifications

How much to tighten the nuts is determined by the size and grade of bolts, as well as their position. Please refer to your manual for torque specifications.

For this bin, the wall sheet bolts were 3/8-inch, and their steel quality was 5 grade.

⅜ on walls=38 foot pounds.

In general, you want to tighten the nuts until they are singing soprano.

Listening carefully will soon allow you to determine by sound how much is just-enough versus too much torque. Try not to strip bolts, but don't under-tighten them, and so give yourself problems in the future. Leaks are no fun to fix, and nobody wants spoilt grain (or a leaky grain bin home).

Stiffeners=looser, due to up and down movement making parts more fragile. 32 foot pounds on ⅜ bolts, and 17 foot pounds on 5/16 bolts.

Remaining Rings

The remaining rings are built and tightened similar to the first and second.

Sealant is applied on horizontal seams whenever the guage of the sheets changes. This may be more frequent or less frequent depending on the diameter and height of your bin. Heavier sheets are required on the lower rings to ensure strength as the pressure of the grain increases.

Stiffeners

Stiffeners should be installed if you have any doubt that your bin will withstand the weight. These are U-shaped vertical iron pieces bolted onto the outside of the bin at intervals. Install them now if needed, as not only do you risk damage to your bin if installation is delayed, but it is much more difficult later, especially if your bin is on a hopper.

No Stiffeners Here

At this time, I am not prepared to talk more about stiffener installation. Just use common sense, and avoid using them where ground tremors occur, as the bolts may sheer due to vibration.

Walls and Floor Grain Bin Construction

Pausing Work

Before you begin building your bin, think about the best way to protect it from wind damage during non-construction hours. The last thing you want to be responsible for is a grain bin shaped kite rolling through someone's yard. As your bin continues to be built taller, the danger of this happening increases. A nearly-built bin is a hazard.

Please take every precaution to protect both your investment and people throughout the building process.

Below are some ideas for stabilizing your bin during off-hours.

Next Day

Make beginning work the next time as simple as possible. Leave your worksite uncluttered, and make the next-day's materials easy to get at while they are in storage. Keep tools picked up and in good working order.

Re-entry

Be sure not to completely install the last sheet of a ring prior to pausing. As shown below, tack it with bolts so you can get back into the bin without fuss, to set the lifting ring, etc.

Changing Lifting Methods

Because our forklift was not big enough to use to finish building the bins shown in this article, we were forced to change our method toward the end. Our forklift boom extended only far enough to complete five rings of a six-ring bin. So we hired a crane while building the last ring and setting the bins on a hopper. If you cannot change methods on short notice, choose the lifting method that will allow you to finish your project with a minimum of fuss.

As we required a crane to set the bins on hoppers, jacks were out of the question for this project.

If Mounting Your Bin on a Hopper

If you plan to mount your grain bin as a hopper bottom bin, don't tighten the bolts on the last ring. Your bin will need to expand slightly to fit over the hopper rim. Sometimes the last few inches of bolts being loose is enough; sometimes more give is required. Ocassionally a wall sheet must be temporarily removed as the bin is mounted.

Ladder Installation Overview

Ladders are shipped in sections. On the featured bin, most sections were 6 feet long, with the exception of the top piece which was only 3 feet. Hardware is provided for installation.

The ladder is installed one section at a time as the bin is under construction. As each ring or couple of rings are finished, the ladder is bolted on and the hardware is tightened. Ladder placement must be kept in mind as bolts are plugged and tightened during sheet installation.

Variations

If your ladder is very different from those shown here, you will have to think through the best installation method for your style of ladder. Some require welding or other measures.

Impact Wrenches--Battery Operated?

It is interesting that as of April 2020, there were almost no video comparisons of impact wrenches which were not battery operated. We have never used a battery operated model on grain bins, because we never found one that will keep up. A good wrench operator can tighten up to three bolts every second.

If you think you have found a winner, please comment below, so all readers may benefit from your experience.

6 Impact Wrenches Compared

Pneumatic VS Battery Operated Impact Wrenches Compared

Understanding Impact Wrenches

Stiffeners

Stiffeners are U-shaped lengths of galvanized steel that are bolted at intervals around the outside of the bin walls, to strengthen the bin and prevent it from collapsing under the pressure of the grain. To aid in dealing with ground vibrations, some have slots in which the bolts go, so minor sliding of each stiffener may occur over the years.

We cannot show you at this time how to install stiffeners, but look into them if you have the slightest doubt about the integrity of your bin walls.

Behlen Stiffeners

These Behlen brand stiffeners were up at auction.

These Behlen brand stiffeners were up at auction.

Your Favorite Impact Wrench Brand

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This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.

© 2020 Joilene Rasmussen

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