Keep it in a bucket with soap and water so it doesn't dry out. Pre-cut a few lengths at a time so you won't need to mess with it too often.
Nylon
A line trimmer, also known as a string trimmer, is used to trim grass or weeds. The piece of equipment also goes by the name of a weed eater, or weed whacker.
Yes it can, but the line does not last as long. My experience has taught me that the smaller the line the shorter the lifespan.
If this is in fact an Echo SRM 210, then a manual is linked below.
It is easy to string a dual line Remington trimmer by following the instructions in the manual. The manual was supplied with the trimmer when purchased.
You can expect to pay about $5 for replacement line for a Poulan Pro trimmer.
http://lawnandgarden.manualsonline.com/manuals/mfg/weed_eater/545117526.html?idRes=15826863 This link should let you obtain the manual for detailed instructions with photos.
craftsman
Locate the trimmer head at the shaft. Remove debris in the head. Cut a 14-inch piece of the trimmer line and fold it. Place the spool against the spindle. Feed the ends of the line through the eyelets. Push the spool down and pull the trimmer line tight with your hands. Tighten the spool.
The return fuel line is loose or damaged. I have the same issue if you are talking the return fuel line. Here is a site I found a diagram on. http://www.ereplacementparts.com/bolens-bl100-41bd100g965-gas-string-trimmer-parts-c-27272_27749_27758.html
Weed trimmer line is made from hardened monofilament nylon of varying thicknesses. PA6/66 copolymer nylon is commonly used in weed trimmer line.
According to the Home Depot website there are two best sellers. They are the Weed Eater 200 mph 430 CFM gas blower/vac, model VS2000BV at a cost of $99.00 and the Weed Eater 9" electric line trimmer, model mini trim auto at a cost of $29.96.