May one insert the wick into the float, used in oil candles, on Yom Tov?

The issue involved is making a k’li – makeh b’patish. One’s initial reaction is that it cannot be makeh b’patish as one is merely inserting the wick into the float. It is inserted without force or technical know-how, so what could be the problem?

Indeed we find that one may not insert feathers or down into a pillowslip for the first time because one is making a k’li. [1] Even though it is quite simple to insert down into a slip and this does not require force or craftsmanship, many Rishonim [2] say that it is an issur d’oraisso (a biblical violation).

So is it permitted or not?

In the previous shiur we learned that on Yom Tov it is permitted to insert a thread into a needle, [3] even though one can argue that the two now become a k’li and it should be ossur. The explanation is that the needle is merely holding and pulling the thread does not make it a complete k’li. So too we can say that the float holds the wick and prevents it from sinking into the oil, [4] therefore it does not become a k’li.

To me it looks the perfect k’li, why should it be permitted?

For many years we were accustomed to threading a wick through a pipe-like holder on Yom Tov and it was never considered making a k’li. The holder holds the wick in the center of the oil container and prevents it from sinking. The floating wick is the same idea only more sophisticated and its insertion is not ‘making a k’li’. [5] Other rabbonim are stringent and say that it does involve makeh b’patish, and as usual one must ask one’s rav.

What's the issue with playing Lego on Shabbos?

Fastening items to each other in a sturdy manner involves makeh b’patish because a complete item is manufactured in the process. Even if one did not complete the item on Shabbos, the issur of making a k’li will still have been violated because it is part of the process. For example, assembling a baby’s crib on Shabbos with screws, nuts and bolts is an issur d’oraisso of making a k’li. It is likewise ossur to assemble half the crib on Shabbos. Assembling Lego would appear to be the same.

However, Rav Shlomo Zalman Auerbach says they are not the same.

Lego can be compared to a baby’s bottle which may be opened and closed as needed.

What can be wrong with closing a baby’s bottle?

A baby’s bottle without the teat is useless and one may close it on Shabbos because it is not a permanent closure. In order to reuse it, it must be opened again. Lego pieces are also assembled temporarily and in order to continue playing one takes the pieces apart. So even though models and designs are created by assembling pieces together, they are never seen as a completed, finished product because the intention is to take them apart for further use. [6]

On the other hand, permanent Lego, such as pieces exhibited in displays, would be ossur to assemble on Shabbos because of their permanence.

May one remove clothes tags?

Here too the issue is makeh b’patish, because one might view the removal of clothes tags as finishing the product.

Indeed the Shulchan Aruch writes [7] that one may not remove fringes [8] left over from the weaving process on account of makeh b’patish- completing the garment.

One difference is that the price tag is not affixed to the garment as part of the manufacturing process; on the contrary, it is added after the completion of the garment. Another major difference is that the tailor or manufacturer would not sell a garment with the fringes attached to the garment, because it would be selling an unfinished product. The price tag is affixed to a finished product and hence its removal does not complete the product. [9]

Rav Shlomo Zalman Auerbach explains that one need not be concerned with tearing either because the tag was never intended to remain attached to the garment. [10]

May one straighten a bent fork?

It happens often at a simcha that one happens to be landed with a fork with crooked prongs. Straightening the prongs can involve an issur of makeh b’patish because one is completing – mending the product. The Magen Avraham writes [11] that one may not straighten a bent needle on Shabbos even when it is only slightly bent. Accordingly one may not straighten a bent knife or a spectacle frame handle because it repairs the k’li. [12]