Heat welding vinyl flooring alone is difficult enough. Now try heat welding the vinyl when it is run 4”– 6” up the wall. Now this becomes a serious installation challenge. On top of that, most of this difficult work goes out for bid, and the lowest bid is taken. A proven installer who can flash cove and heat weld does not come cheaply and getting the low bid does not always guarantee the most proven installer will be doing the work. You generally get what you pay for. Flash Cove heat welding is an art and takes a lot of talent to do it correctly.
In my opinion, there are 3 steps in the flash coving and heat welding process;
1) Fitting of the material. The better the material is fit, the simpler the heat welding will be. Leaving large, inconsistent gaps at inside and outside corners makes the welding more difficult. It is fine to leave a small gap at the seam for helping to rout out the material. Please remember, this gap at the seam should only be the thickness of a knife blade. Also, having a consistent groove (depth and width) also helps simply the welding process and gives a better appearance to the flash cove welds. A tool that is very useful for routing out these vertical seams is the Turbo Cove Groover (see below) available at Turbo Heat Welding Tools 714-522-4290
2) Heat Welding of the Flash Coved Seam. Flat lay heat welding is hard enough, but when heat welding vertically it gets even more difficult. There a few things that can simply flash cove welding;
A. Welding Gun. Conventional Heat Welding Guns are large and cumbersome. Leister makes the Hot Jet S, which is a smaller, lighter Welding Gun specifically designed for flash cove welding. This gun allows you to control the heat and the fan speed which gives the installer a little more control of the welding process.
B. Welding Tip. Using the correct tip can make a huge difference. Using a welding tip designed for floor welding may not be practical for flash cove welding. Having a welding tip with a longer nose will keep the heat to far from the flooring and not allowing the weld rod to fuse properly. The nozzle I prefer is the WDD 722 from Winkelman Sales. I use this nozzle for flat lay welding as well as cove welding.
C. Position of the Nozzle on the Welding Gun. Having the Welding Tip positioned upward also keeps the needed heat close to the flooring to achieve the proper welding temperatures.
3. Trimming of the Weld Rod. This is probably the most critical step. The object is to make these welds not stand out to the visible eye. Trimming and smoothing out these welds can help take the human eye away from these seams. Unfortunately, all the good skiving (shaving) tools used for the floor are not useful on the walls and coved areas. Basically, you will be using Exacto Knives to shave the weld down flush to the flooring, then smoothing out these welds to eliminate any chatter marks when trimming of the weld rod. I have seen installers also use the knife blade from their Mozart Knife to shave the weld rod flush to the flooring.
After the weld rod has been trimmed, I use the 3/8” Bullet (#WDD658T) from Winkelman Sales to smooth out the weld rod and eliminate and rough weld rod. The Bullet goes on the welding gun and gets hot and allows you to smooth out the inside and outside corner seams.
Another tool useful for smoothing out welds in the cove area is the Hot Smoothing Tool (#WDD984) from Winkelman Sales. This tool heats up and softens the weld rod and smoothes out any chatter marks. It also has a blade for smoothing out weld for a booted corner.
I have used some terms referring to corners that everyone may not be familiar with, so I added some illustrations to help clarify these terms.
Another solution for eliminating the need for fitting and welding these corners is using the Flexco Health Design Wall Base. Health Design Wall Base has Preformed Inside and Outside Corners were specifically developed to increase productivity and ease of installation compared to traditional time consuming and unsightly on-site flash coving, especially related to corners. Material is designed to be heat welded to recommended FLEXCO® vinyl and rubber flooring products along with competitive heat-weldable resilient solid vinyl tile and vinyl sheet flooring.
This unique system also provides an almost seamless application allowing ease of cleaning while aiding in the prevention of bacterial growth. Heat Weldable Wall Base and Corners are also flexible, which not only makes installations fast and economical, but it helps conceal floor and wall irregularities while providing a tough finish to resist scuffing and gouging. The color is homogeneous throughout the entire thickness of the wall base. The surface texture is an appealing unique matte finish to ensure an attractive transition.
When installing the Health Design Wall Base it is recommended to use the Vinyl Welding Rod for all Base-to-Base and Base-to-Corner seams. The only time you need to use the Rubber Welding Rod is when you are installing the Health Design Wall Base with our Rubber Tile, Sheet or another Linoleum type product. The majority of these installations are now occurring with Vinyl Sheet products in which the Vinyl Sheet manufacturers welding rods are being used for the Floor-to-Base seams. This is fine and all manufacturers welding rods will adhere and work with the Health Design Wall Base.
Suppliers mentioned in this article
Winkelman Sales 1-800-929-4326 http://www.winkelman-sales.com/files/68377630.pdf
Turbo Tools 714-522-4290 http://turboheatweldingtools.com
Flexco Health Design Wall Base http://www.flexcofloors.com/products/healthdesignwallbase