My own talleisim ketanim have lasted for years, and I’ve replaced the tzitzit several times. But for most people replacing tzitzit strings is not such a simple proposition, and they would prefer to keep them in good condition for as long as possible. Here’s an inquiry we received this week:
Hi- great website!
Do you have any advice on making tzitzit last longer? You know: they get fragile with wear, and start to break off easier. Any way to make them last longer? (Maybe someday tzitzit will have some fiber like kevlar added…) As tzitzit get older, with washing and (probably) friction against pants, the strings wear and break easily in different places, which probably wouldn’t happen if the strings were synthetic…Also, I once heard that someone had a way of dipping the strings in some liquid, but lost the reference.
I would say the most common problem is tip fraying. Some people avoid that by tying a simple knot right near the tip of each string. This is a bit problematic, because according to some opinions you would be adding to the number of knots. And if you ask me, it doesn’t look so nice.
It’s fairly common to dab the tips with clear nail polish or glue. This is a bit time consuming. I’ve heard some people use melted wax from Havdalah, but I don’t know how well that works. It offers the advantage of using a mitzvah object for a second mitzvah (הואיל ואתעביד ביה מצוה חדא נעביד ביה מצוה אחריתי).
On a side note, some people get frustrated over the last double knot unravelling. This is especially aggravating on Shabbos, when you cannot tighten the knot. One online tzitzit seller even markets a permanent knot they refer to as kesher shel kayama. This is a bit of a question from a halachic standpoint, because you need to have four strings, and some poskim hold that this renders it a single cord in some respects. (This parallels the big question of ohr echad when it comes to tefillin.) I have had good results by simply pulling that final knot really snug, holding it under a thin stream of hot water for 10 seconds and then letting it dry.
Some manufacturers are better than others. I have seen some tzitzit that get frayed really badly, very quickly. My own tzitzit sometimes form bends near the end. I tie mine longer than the minimum length, and then snip of the tips when they no longer look nice. Of course some people have a custom not to cut tzitzit with metal, and ceramic scissors (i.e. zirconium oxide) are both expensive and hard to come by.
I don’t know about synthetic. Tzitzit have to be made of the same material as the בגד, i.e. cotton tzitzit for a cotton beged, or wool tzitzit can be used on any beged (except linen, in the absence of techeiles). That’s why 99% of all tzitzit strings manufactured today are made of wool.
But what about say 90% wool and 10% kevlar? I don’t know about that. That’s a question for a posek. I’m really not familiar with issues of fabric blends. Of course there are plenty of people who wear a 60% cotton/40% polyester tallis katan (especially among chassidim and small boys).
Even if there is no halachic problem, there would still be a practical problem: tzitzit tend to get dingy over time (with young boys, in a very short period of time), and getting them white again can be quite a challenge.
One solution is to acquire proficiency in tzitzit tying, so that you can sit down on the couch, relax and tie new tzitzit in half an hour flat.
We have an in-house tzitzit tie-er, but occasionally I’ll take one or two home and tie them to unwind (no pun intended). After several years in the business my hands can tie just about any tying custom without engaging my brain much, so it’s actually a bit therapeutic for me. But the majority of my customers are not prepared to tackle tzitzit tying, so I realize this is going to be a solution only for a minority of people.