Illustration A

The number of seam tapes available to the installation community is almost too numerous for the mechanic to decipher and make an educated decision about. We are all creatures of habit, and the old adage "If it isn't broken, don't fix it" is the saying I hear most often when talking with installers. But the fact is that you seldom hear the mechanics state, "This was the easiest carpet I ever seamed," and why is that? Well, because all the installers I talk with could not say it! The reason is that the carpets aren't getting easier to seam. Remember when Soft-Bac first hit the streets? Yeah, you remember the problems everyone had. Most of them could have been avoided if the installer had gone to a clinic or joined the local CFI chapter and attended the meetings. Our local chapter has question and answer (or challenge the rep, as we say) time set aside just for this purpose, to help them perform better at the art of installation; and it is, without question, an art. So, let's take a look at some of the most common problems associated with seaming irons and the use of hot-melt seam tapes.

The key word is HEAT; you must heat the tape to get the ideal melting point and viscosity properties in order to adequately penetrate the carpet's backing system. But, apply too much heat and you cause several other problems that will affect your art work.

Carpet backing delamination:

Excess heat can affect the latex binders used in the making of most common carpet backings. Too much heat can cause them to degrade rapidly and break down. The result would be a seam that was bonded on the base but would still peak since the bond between the primary and secondary backings had broken.

How do we prevent this? Turn down your iron setting. Using a low melt point seam tape is the only way (Illustration A and Photos 1-4).

Pad compression:

Many urethane rebond and other carpet pad types are also sensitive to excessive heat. Leaving a hot iron in one place for an extended period of time will cause the pad to compress and lose resiliency. This will result in a channel (lower profile) running the length of the seamed area (Illustration B and Photos 5-7). How do you avoid this? Seaming on a hard surface ensures tight seams and proper hot melt adhesive transfer, and low melt point seam tape should be used.

Carpet pile deformation:

Carpet texture is created using a heat process. Adding heat back into the material (face yarn) and then crushing it or deforming it with the wrong type of seam roller or the wrong type of seam weight can re-crimp the face pile, leaving a telegraph of where the seam was placed (Illustration C). How do you prevent this? Never use a star roller on a hot seam; always seam in the direction of the pile; and use a heat-dissipating seam weight.

Illustration B
Never use your metal tool box tray, and use low melt point seam tape.

Seam tape bonding to the pad: Allowing the iron to get too hot over most any tape or not moving a hot iron fast enough can cause the hot melt adhesive to bleed through the paper, causing it to adhere to the top of the padding. This becomes a problem during the stretch-in process, and can cause a bunching up effect of the pad under the carpet (Illustration D). How do you avoid this? Use a low melting point seam tape.

These are the most common problems we see in the field on a daily basis, but not all of them. Proper maintenance of your equipment, like cleaning your iron, is a must to ensure performance. Remember the saying, "A dirty engine runs hot"? Well, this is also true of your iron.

And, when you do change to a low melt point seam tape, please clean your iron; the old adhesive will mix with the new and cause excessive smoke and odor. Look at it this way: your iron will last longer at a 2-3 setting than it will at 4, so you're saving money right there.

If you aren't familiar with low melt point seam tapes, then You Make the Call to your friendly local floor covering distributor and ask them; they will be more than happy to supply you with the information and expertise needed to help you turn it down (your iron, that is).

Illustration C
I would like to thank Jeff Johnson of Capital USA for allowing me to use his graphics and illustrations.

Illustration D
And remember, every installation that you do is left with your signature. Do them with pride and the quality will speak for you and your ability. Again, thanks for reading and have a great day!