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(Preliminary note: Fluorocarbon strings are often mistakenly referred to as “carbon” or “carbon fiber” strings. Fluorocarbon, or PVDF (polyvinylidene fluoride) is an extruded plastic polymer, similar to nylon but with different mechanical properties. Like nylon, it contains carbon molecules, but it otherwise bears no resemblance to carbon fiber, which is black!)
There are a couple of different ways to approach this question. The most basic answer is that you could string a Dusty Strings harp with fluorocarbon, provided you did your research on density, lowered the string gauges to keep from overloading the harp, and swapped out sharping levers to match the new string gauges. It wouldn’t be an easy switch, but it would be possible. We don’t have a direct conversion chart to recommend, so you’d be on your own for experimenting and sourcing strings.
The more nuanced answer is that, while fluorocarbon strings sound wonderful on certain models of harp, they aren’t particularly pleasant on a Dusty Strings harp that was optimized for nylon strings. When we did tests of three identical bubinga FH36S models, one with nylon strings, one with lever gut, and one with fluorocarbon, the general consensus was that nylon sounded beautifully clear and bright, that lever gut sounded lovely - just a little warmer, rounder, and less bright than nylon - and that fluorocarbon sounded so exceptionally bright and sharp that it was unpleasant and piercing to the ears.
The reason for the difference has to do with the different material properties of fluorocarbon and nylon. Without diving too deep into the physics, we can say that harps are commonly designed with a particular type of string in mind, and the string material and harp design go hand in hand. If you change to a string material with significantly different properties, you are going to get significantly different results.
In the case of a Dusty harp that was designed for nylon strings, those nylon strings have a nice medium tension and a clear, bell-like tone. Changing to fluorocarbon results in strings that feel exceptionally tight, sound so bright as to be somewhat shrill and harsh, and are likely to be more prone to breakage. This is because the string lengths are just a little too long for fluorocarbon to work well. In the top of the range especially, fluorocarbon strings become dangerously close to their breaking points, which could be a costly nuisance!
However, there are other makes of harp on which nylon strings might feel somewhat loose and would produce a less than clear tone, but on which fluorocarbon strings feel and sound quite good. These harps likely have shorter string lengths. A harp builder might choose to optimize their harp for fluorocarbon in order to achieve a clear and focused tone with a lighter feel than nylon or gut.
All of this means that it’s rather pointless to debate the tonal merits of a particular string type without considering a particular harp make and model at the same time. Poor tone or tension is not the fault of the string itself. Rather, it’s the harp’s design and the pairing between the string and the harp that determine how well that string will perform.
When considering if you want to change your Dusty harp to fluorocarbon, you might ask yourself what you are hoping to achieve. If you’re looking for an even brighter tone than your harp currently has, and if you’re willing to suffer through the string breakage, fluorocarbon strings might do this for you. (See above for what would be involved in making this switch safely.)
If you’re looking for a more mellow tone, or strings that have the feeling of more firmness and grip to them, you might consider lever gut. On a Dusty harp, gut produces a slightly warmer sound than nylon, and the strings feel a bit stiffer, giving the impression of more resistance without a dangerous increase in tension. Keep in mind that gut does break somewhat more than nylon, as it’s a natural material. We have lever gut string sets available for most of our harp models. (See also: Can I replace my nylon harp strings with gut?)
If you’re looking for lower string tension or strings that feel thinner and more flexible, you could try smaller gauges of nylon. However, this change would require swapping out sharping levers, which are configured to work with specific string diameters. We don’t offer a light-gauge nylon string set, but you could try what we’ve done on the Serrana 34, which is to go one gauge lighter on all the monofilament strings.
If you like how your harp sounds and feels, and you have simply heard that fluorocarbon strings are better than nylon strings, then there’s probably no reason to make a change! (They are more expensive and can be more difficult to find, but that doesn’t equate to higher quality in this case.)
For those who are still curious, here are a few other things we’ve learned over the years about fluorocarbon strings and how they compare to nylon:
Further reading: Can I replace my nylon harp strings with gut?