Thermoplastics change the game for tank fabrication


by Paige Kistner, Seelye Acquisitions, Inc.


n the realm of tank fabrication, thermoplastics have emerged as a game-changer, offering a versatile and innovative solution for custom manufacturing. One of the major benefits of fabricating with thermoplastics is the flexibility that it offers in design and production.

Fabricating with thermoplastics has become somewhat of an art form throughout the years. With the numerous options one has to fabricate using thermoplastics, designing with plastics is now almost limitless.

20 foot water holding tank

20 foot water holding tank fabricated by DJ Plastics, a division of Seelye Acquisitions, Inc.

Tank applications

Deciding which procedure will work for your application depends on a number of factors. An important aspect when choosing the proper fabrication process for a tank is the durability and longevity. A water tank being installed in a RV or Custom Coach for instance needs to be durable. If the tank cannot handle being jarred or having fluid sloshing constantly the user is going to find that the tank will not hold up well and there will be additional costs repairing. So, purchasing a thinner wall roto-molded tank may not be a good choice for this application; while, a custom fabricated butt, extruded or bead welded tank may be.

Price expectations

Price tends to be the main deciding part as to what style and type of tank people purchase. Depending on what style and type of tank is needed, prices can range from economical to extremely expensive. Pricing on tanks is like any other purchase; you tend to get what you pay for. If your need requires light-weight, no seams, are readily available and are fairly economical, roto-molded plastic tanks are a good option. However, depending on the wear and tear on the tank, roto-molded tanks normally cannot be repaired due to the thin wall of the tank and may need to be replaced earlier than other tank options. Custom fabricated thermoplastic tanks, although can be expensive, typically are an ideal choice when durability, fit and longevity are most important. Plus, one of the many benefits of working with thermoplastics is its recyclability. The ability to repair, reprocess and reuse these materials reduces waste and lowers production costs.
“One of the many benefits of working with thermoplastics is its recyclability. The ability to repair, reprocess and reuse these materials reduces waste and lowers production costs.”
plating tank
Plating tank fabricated by DJ Plastics, a division of Seelye Acquisitions, Inc.

Welding methods

When it comes to having a tank custom fabricated there are additional factors that need to be considered. For example, how the tank is welded has a direct influence on the structural strength of the vessel. The most common types of welding options available are bead welding, extrusion welding and butt welding. Bead welding is a good option for smaller sized tanks and plastic sheet gauges up to approximately ½ inch thick. Bead welding is welding a piece of plastic welding rod, ranging in thicknesses of 1/8, 5/32 and 3/16 inches diameters, into a beveled edge or seam using a hot air/gas plastic welder. With proper technique and temperature, a bead weld is typically 90% to 100% as strong as the base plastic. For larger size tanks and sheet thicknesses of ½ inch to approximately ¾ inch, it is recommended to do both bead and extrusion welds. This technique requires having two hot air/gas welders, a bead welder and an extrusion welder. An extrusion welder melts the welding rod into a wider mass of material allowing the user to cover a larger area or longer seam. Laying a bead weld into the seam of the tank and then extrusion welding over the bead weld helps ensure the tank is water tight as well structurally sound. Working with thicknesses of 1 inch or more, butt welding will give the strongest bond possible. A butt welder heats the ends of two sheets and then presses them together to fuse.

plastic tanks

Seelye Acquisitions, Inc.

Benefits of a custom fabricated tank

Another selling point for custom fabricated tanks is creating a tank that can be made to fit the customer’s exact needs. Having to retrofit an area can be one of the biggest expenses of any job. Not only will retro-fitting an area to fit the tank cost more due to additional material, but it will also take additional time. As we all know, in business, time means money. It may also result in lines not able to run as smoothly, making the flow more difficult. Access to the tank may be impeded for cleaning, viewing or, when needed, repairing. Designing the tank to fit perfectly into a production area means systems run more streamlined and in the long run, it means, saving money.

Custom fabrication is no longer out of reach. Taking the time to research all the options of thermoplastic tanks will help save money in the long run. With the correct information and knowledge, custom fabricating may just be the right fit.

Paige Kistner is President of Seelye Acquisitions, Inc. For more information contact Seelye Acquisitions, Inc. at 946 Century Lane, Apopka, FL 32703-3709, USA; phone (407) 656-6677; email customerservice@seelyeinc-orl.com; or www.seelyeinc-orl.com