I've been tying a bunch this winter/spring. Love using Hard As Hull head cement or Helly Hanson nail polish. By the time I get to the second half of the bottle, It has thicken up to be too hard to use. I'm really not too cheap to buy another bottle, I just hate waste. Any experienced tyers have a thinner they have used with success? I'm careful to close the cap between uses but still gets thick. Thank you.