hi guys new here and had a question. i’m sure its been asked before or there are topics on it, but i didn’t find any when i did a search. i’ve done a few boards now, but i’m having the same problem with everyone. i keep getting these groves in the rails and hard edges in the rails. i’ve tried sanding the rails by hand but they seem so uneven in resin amounts that i get nowhere. so i’ve started to sand them with a sander. after i sadn to 220 grit the rails feel pretty good and smooth, but i’ve taken down so much of the hotcoat. so i add another light hotcoat to the board, taping in the middle of the rail and tring to match the tape line for the other side. then i start with 220 grit and work up to 600 grit. and now i’m having these groves again. so i’ve tried a few things. just sanding the rails with 600 grit (not wanting to take off too much resin) but off course that really isn’t taking out the groves. i’ve tried starting very lightly with 320 grit then going to the 600, which helps some what but still groves and not a smooth curve on the rail. i’m scared to go with the 220 grit to start because of buring thru the resin too much. any advice?
sounds like you are doing your hotcoats too fast and leaving the trace of the brush on the rail> try slowing your mixes down to give the resin time to settle and flatten. Its easier to resand rail and try a sloower mix!
hey grom is this for a sanded finish or are you trying for a gloss coat
huie
i guess its for a sanded finish, i’m not using gloss resin. i’ve been doing the second coat to fill in, and give it a cleaner look. is there a site that has the cataylst charts with times of curing? because i have just been eyeing some cataylst to the resin. the resin been buying doesn’t come with a chart.
ok what temp are you working 11/2 percent cat of the amount of resin is ok normal temp i am in aus norm temp 30 deg cent is preety norm
how about telling us what you have done so far did you glass the board yourself
i would assume you have hot coated it so i just cant quite figure out
wats going on have you got a pic
What type of trees are in these groves?
Howzit littlegrommy, There is a different technique you can use. Don’t tape off the rails, just hotcoat the deck all the way to the just past the rail tuck line then use a sqeegee to remove excess resin by holding the squeegee facing up along the bottom all the way around the board. This will leave some sanding resin on the bottom laps but it will be removed when you sand the laps to blend the glass before hotcoating the bottom.Hope I explained this so you can understand it. But if you are going to tape off the rails then you have to sand the seam and when you hotcoat the bottom tape off just past the seam so the resin over laps it.Aloha,Kokua
i guess its for a sanded finish, i’m not using gloss resin. i’ve been doing the second coat to fill in, and give it a cleaner look. is there a site that has the cataylst charts with times of curing? because i have just been eyeing some cataylst to the resin. the resin been buying doesn’t come with a chart.
Not with curing times, but maybe it’ll help your with your eyeballing:
http://www.fiberglasssupply.com/pdf/miscellaneous/MEKPChart.pdf
ok as far the temp, it varies. i do the resin work in my parents garage and it can vary from around 55 F to 80 F in the winter and 80 F to upper 90’s F in the summer. I don’t have it temp controlled, but i do bring a thermostat out with me. now the eyeballing, i use something to measure how much cataylst and resin i’m using but i don’t know how much to use at different temps and for the different curing times, that’s why i need to find some kinda chart for that.
now let me go thru how a do my resin work. after the board in laminated i take a surform to the high spots and around the rails to try and make it even and smooth. then i do the deck of the board (no tape), i take the brush along the bottom of it to take away some of the pooling hotcoat. after that has cured (or somewhat cured) i take razor to the bottom to take off those drips of resin. flip the board tape on the bottom for the rails and do the bottom. when it has cured somewhat i remove the tape. let it sit for 24 hours then sand. starting with 80 grit to take down the leash plug and fin plugs. then starton the board with 120 grit, to moving to 220 grit. i do use the sander on the rails at low speeds 220 grit (as the rails are uneven after the hotcoat) then i go over the rails by hand with the 220 grit. clean the board and put a second hotcoat on it. i tape in the middle of the rail and mix up some resin to cure “fast” (although as i said not sure how fast), i then put it on like a glosscoat and paint it on (not too thick), then walk it out. remove tape after it starts to kick, flip board and try to make the tape to the other tape line, but keep it a little away. do the same for the bottom of the board as the deck. let it cure for 24 hours. then i sand again, start with 220, then 320, then finish with 600. after that i go with a 3m super fine scotch brite. now as i’ve said i’ve tried doing the rail with only 600 grit on the finsh sand, i’ve tried hitting it lightly with the 320 then the 600 grit on the rails and still get these groves (channels) and sometimes hard edges in the rails.
i tried to take a pic but it does show what i’m talking about. i didn’t have the same problems in the past and i try to think what is different. i also get these “waves” in the rails during my hotcoat where it looks like the resin is running down or places where where the resin seems to of moved of the deck and the weave is somewhat exposed. is that because of the cure time? do i need to increase or decrease the cure time? thanks for the help so far.
Speed up the cure time with a little extra catalyst so that the resin kicks faster and doesn’t have time to flow off the rails. Also make sure you wet out the tape line. This is something I learned from Kokua. Resin will travel the path of least resistance, so if there is already a wet path it will continue to run that way because of the surface tension or something. If you run your brush around the tape line making sure to wet it all then the resin will flow evenly everywhere. You can see this principle at work when laminating. Let one drip run off the rail and the rest follows and the path doesn’t get any wider.
You may also be getting some slabbing on the rails, but they’re usually larger than the grooves you’re talking about and you would notice. Let me know if that technique works for you. I’ve had similar problems with hotcoats in the past where sometimes there would be completely bare spots on the rails and it was all because I didn’t wet the tape.
thank you everyone, great tips. i’m now sure that the reason for my problems was the fact the my “hotcoats” weren’t kicking soon enough, which was something i thought of been the problem as i didn’t seem to have the problem on one of my first boards. but that was before i started doing the double hotcoat and sanding to 600 grit. i also kinda found, put to together a catalyst chart by combining info from a lot of sites. i’ll post upadates after i do my next board. thanks again.