Appreciation post: that $12 seam iron from the swap meet in Fresno saved me on a 4 hour stretch job
I used to think a regular old iron and a wet towel was good enough for every seam, until a 40 oz carpet in a hot garage in Clovis had me fighting the same seam for 3 hours with fraying edges. Bought a used seam iron off a guy at the swap meet for $12 and the next seam took 20 minutes, so what's your go to for heavy berber, iron or something else?
Heavy berber is a whole different animal (those loops fight you the whole way). I run a cheap seam iron too but the trick that saved me was cranking it hot and using a seam weight right behind it instead of pressing down hard. Let the heat do the work and keep the iron moving, don't park it or you'll melt the backing. A little spray of seam sealer on the edges before you close it up helps a ton with fraying.