Well, it says "Rosin2". There is no guarantee that the advertisement was reviewed by a person fammilliar with the subject. This is Amazon, for crying out loud -poorly written copy for technical specifications is nearly de rigueur in Amazon ads. "If it is not written wrong, it isn't right."

 

Everyone else has pretty much covered the solder issue. I think I saw one comment or two about the resistor value.

You've worked out that you need a 32 ohm resistor. However, I don't recall seeing an operating voltage or any information on what amperage you want to operate the LED's at. So I'll go for a generic answer, making up some fictitious numbers for the sake of understanding. If you already know this information - assume I'm trying to be helpful and not a jerk.

Since you said you need 32 ohms I'll start there. Assuming you want 20 mA (MilliAmps), 32 (ohms) times 0.02 = 0.64 volts. (a.k.a 640 mV). I don't see that small a voltage lighting up any LED's. So - again, assuming, you have 12 volts supply and (assuming) 3.2 forward volts (Vf), if you have 3 LED's in series, you would subtract (3.2 x 3 =) 9.6 volts of forward drop, leaving (12 - 9.6 =) 2.4 volts. 2.4 volts divided by 20 mA = 120Ω. Without knowing exactly what you're working with I can't see you needing a 32 ohm resistor. Incidentally, 2.4 volt drop across the resistor leaves you 9.6 Vf for the three series LED's. The wattage comes out to (2.4 x 0.02 =) a mere 48 mW (MilliWatts).

So for me I'm having a hard time reconciling how you're needing a 32 ohm resistor. HOWEVER, if I'm wrong with my numbers and assumptions; if you NEED 32 ohms, you'll find that most common resistors have a 10 to 20% tolerance. You CAN find 5% tolerance and even 1% precision resistors, so a 33 ohm resistor with a 5% tolerance a 33Ω resistor can be 31.35Ω to 34.65Ω. And the difference in brightness - - - you won't be able to perceive the difference.

If you can, please provide more detail about the LED's we're discussing as well as the power supply you're powering them with.

 

For something like an LED, you don't need to run at max rated current, a precise resistor value is not required. Pick up a kit like this:

https://www.kr4.us/resistor-kit-14w-500-total.html

If you need very precise values, you might need to combine multiple resistors in series and/or parallel to get the values you need if the exact value isn't available. You can buy very precise resistors, but price is proportional to tolerance.

 

So, will 20 lead to burn out, and is there anywhere I can buy the 32's from?

The closest standard 5% value is 33 ohms which shouldn't be difficult to find. If you can't find them locally, just have them shipped.

You didn't provide enough information to determine whether 20 ohms will work.