I- am losing mostly hair in the frontal, could it be ultrs hold fault? maibe becouse it hard yo get it off?
It is probably because you are pulling the system off before the adhesive is completely released. You should soak the adhesive totally with 99% isopropyl alcohol, through the lace. Use a bottle with a long narrow spout (like an American mustard bottle) so that you can get lots of alcohol onto the lace/adhesive without getting too much on the hair. Then leave the alcohol to do it's work - maybe 10 minutes. The system should then lift off without any resistance. If it does not lift off without resistance, apply more alcohol and wait longer. Once it is off, let the base of the hairpiece soak in more isopropyl alcohol, to release any remaining glue or tape. You should then be able to remove the glue/tape with your fingernail or the edge of a credit card without putting any strain on the hair.
You could also use knot sealer to strengthen the knots.
2- it's true ghostbond xl could turn white?
All glues can turn white if you allow them to get wet before they are fully cured, either by sweating or by contact with water (e.g. swimming). Always apply the glue in a cool dry place, and don't get it wet, and don't do anything sweaty, for at least 3 hours after applying the system. Then you should be fine.
3- Also which glue for the frontal you recommend? i like it stong i think acrilic are the best or i am wrong?
There are 2 types: the normal hair system glues like Ultrahold, Oil Resistant White Glue, Davlyn, Ghostbond etc. which are acrylic based. These are what I would recommend. They typically hold for around 10 -14 days, and can be released with isopropyl alcohol. You may have to experiment to find the one which works best for you. There are dozens of different brands and formulas. Then there are the cyanoacrylic glues (superglue) which some Hair Clubs use. They typically hold for 4 weeks. They can only be released with acetone. I am not a medic, but with the research I have done I am not comfortable that these glues are healthy for your skin on a repeated basis.
4- what about walker 3-mil tape? why is not common?
It is pretty common, and it is very good for hairlines. In fact, it is the only tape I have found that gives an acceptable result for a hairline. It is not quite as undetectable as glue, but very nearly. I use it when I need a stronger or longer hold.
Noah