Seam peaking is a pesky little problem, helped, but not completely solved by the techniques we discussed last issue. Now into the fray come reinforcements in the shape of a new way to seal cut edges. This new technology allows us to seal the seam edges of our carpet with hot glue instead of latex, with the use of a special sealing tip for the glue gun. The advantage of using hot glue over latex (or latex type sealers) is that it cools in 10 to 15 seconds, eliminating the mess potential of latex and the waiting time for it to dry.
As it usually happens with new technology we get not one, but two new and different tips to choose from (Photo 1) Working from left to right, there are actually two tips from Gundlach and one from Orcon. The tip on the far left from Gundlach is for sealing carpets with attached cushion. The middle tip is also from Gundlach and the one on the right is from Orcon, and they are used for all other types of carpet. Both of these tips bolt up to a standard glue gun; I recommend at least an 80-watt glue gun to give you enough heating power. The Gundlach tip comes with an adapter to fit those 80-watt guns. It was designed for a more powerful 250-watt gun, but works just fine on the 80-watters.
Although the tips are used differently, the Gundlach tip is pulled (Photo 2); the Orcon tip is pushed (Photo 3). The result is the same: hot glue is pressed into the cut edge leaving a smooth sealed edge.
Yes, I know you have a couple of questions: What about the mills or the Carpet and Rug Institute? Do they accept thermoplastic adhesive as a proper sealant? What about excess glue getting on the nap? And most importantly, how does this help with seam peaking? Yes, the mills and CRI accept hot glue, and the current issue of CRI 105 reflects that acceptance.
Like any method of applying adhesive you must be careful to use the correct amount. This applies to the use of these two sealing tips as well. If you squeeze the trigger too hard, you can get excess hot glue up on the face fiber. This is not really that big a problem once you practice on a couple of scraps. In my experience, the Orcon tip is a bit touchier than Gundlach tip in that respect. The Gundlach tip is designed so that excess adhesive is directed toward the back of the carpet not up toward the face. This doesn't eliminate glue flowing upward, but does lessen it. I do find it best to brush the nap away from the edge; this just helps to keep the nap clean, whether you are using latex or these hot-melt sealing tips (Photo 4). Brushing the nap back from the edge also helps keep the nap out of the way while constructing the seam.
Seam peaking is in my mind the most exciting aspect of these sealing tips. In the mid 80s, I developed a technique for seaming Berbers using a hot glue gun. It solved all my Berber seaming problems, such as peaking and the fuzz line on cross seams (tune in next issue for more on that), but I couldn't use it on cut piles. It was too difficult to hold the glue gun steady while seaming, and face yarn would get trapped.
With both the Gundlach and the Orcon new sealing tips, the adhesive is applied to both of the cut edges and allowed to cool. When the seam is made, the heat from the seaming iron starts to soften the hot-melt adhesive on the edges. When the two pieces of carpet are pressed into the melted thermoplastic on the seamtape, the heat reactivates the edge sealer, welding the two edges of the carpet together. Remember last issue when I said a seam will peak the thickness of the carpet back, because that's how high the tape had to rise to get in line with the stretch? By welding the edges together with the reactivated thermoplastic adhesive, you have raised the centerline of the seam to get in line with the stretch, thus reducing the amount the tape has to rise to get in line with the stretch by a huge margin. A word of caution here: these tips are not a panacea, a cure all, for seam peaking; it is still advisable to follow the stretching techniques we discussed last issue.
This photo is a cross section of a seam I made using a Gundlach tip, however the end results are the same with either tip (Photo 5). The next series of photos (Photos 6 & 7) are of a seam on which an Orcon tip was used. This is a 15-by-23-foot living room; the way the job laid out, it took a 12-by-23-foot segment with a 3-foot fill; there are 23 feet of windows running the length of the room 3 feet from and parallel to the seam. The carpet is a low, tight, 1/2-inch thick, 65-ounce plush, seamed with 3-inch tape. The photos are from different angles; the hand seam roller is placed on the seam to show its location. The carpet shows footprints or any disturbance of the nap, you can even see the imprint left by a shelf placed on the floor.
The next series of photos (Photos 6 & 7) are of a seam on which an Orcon tip was used. This is a 15-by-23-foot living room; the way the job laid out, it took a 12-by-23-foot segment with a 3-foot fill; there are 23 feet of windows running the length of the room 3 feet from and parallel to the seam. The carpet is a low, tight, 1/2-inch thick, 65-ounce plush, seamed with 3-inch tape. The photos are from different angles; the hand seam roller is placed on the seam to show its location. The carpet shows footprints or any disturbance of the nap, you can even see the imprint left by a shelf placed on the floor.
These sealing tips are quick and easy to use, they eliminate the mess of latex, and they go a long way toward reducing seam peaking. I seam seal every carpet seam, and I haven't used latex or latex type seamsealers since I got these tips last spring. I have used them on cut piles, level loops, Wiltons, flat weaves, and Axminsters.
Either one of these tips will do a good job for you. If you use one of these tips and the techniques I discussed with you last issue, you will greatly reduce seam peaking and solve many seaming problems. I don't care which one of these tips you use; get one or the other and use it! If you don't use one of these new sealing tips, you are doing yourself and, more importantly, your customers a great disservice.
I want to hear from you. Tell me how we can improve.
Michael Hetts is a CFI Certified Master Installer who has worked in the carpet installation field since 1970. He is currently an independent manufacturers representative for Sinclair Equipment, Contec North America, Seam Master Industries and the Carpet Badger.