I am having troubles with my first gloss coat. When I peeled tape after the initial gel I got a bunch of adhesive residue from the tape and 30 hours later I still have various sticky spots (like it never kicked?) mixed in with broad brush-marked areas of kicked and waxed resin. From reading other posts I am concluding that I was low on catalyst (allowing styrene to eat tape) and overworked the smoothing with the chip brush (hence the brush marks).
Is there is anything I can do to the sticky spots to have them kick or dry?
Resin is Ferro Marine Clear (ISO/NPG), doped with wax+styrene at the supplier. Manufacturer recommends 14-20 mil coating, I mixed for 18 and still had an ounce or two left over. Tape is 3M 233+, P/N 03431. I stirred the resin a bunch before 1.5% catalyzing. Shop was mid 70’s during application and then I put the board in the rafters (above door height) for high 70’s/low 80’s overnight. Shop is heated with radiant heat, so not much airflow other than when I walk in and out. Once the board was in the rafters I did open the door to let the ‘stank’ out for a few minutes.
Hey Jrandy
I’ve had the tacky bits under the tape problem from using inferior tape - where the adhesive seesm to get disolved and mix in with the resin. All I do under in this situation is to go along the rail stick down fresh masking tape and then whipping it off (like they do when they remove hair with wax strips). That will get rid of most of the gum. Then I go over with a paper towel soaked in acetone and give it a bit of a scrub - comes out perfect. That wont help you out with your tacky bits on the rest of the job but if you do this to rails first then reshoot the gloss you’ll have a perfect job.
Cheers
Rich www.thirdshade.com
Uncured sticky spots in either a gloss coat or hot coat are usually from brushing too much. Once the wax rises to the surface you don’t want to disturb that air barrier that the wax forms. A bit of a ‘cheat’ is to cover the sticky areas with wax paper for about a day. Get it good and flat. Not a foolproof thing, but it sometimes does the trick.
The tape trick worked great on the adhesive residue.
Waxed paper over sticky gloss resin worked pretty good, most of the gloss has hardened. Cling wrap creates wrinkles in the wet resin- I put some on until I could get wax paper. In retrospect it was not a good idea...
Do I need to do anything with the surfacing wax before sanding?
Rich mentinoned 'reshooting' gloss. Is this a reference to using a spray rig? My supplier seemed surprised that I was using a brush.
Thanks LeeD. It was more gooey wet than tacky dry, I was afraid to smear it around with the sander.
I am not trying to get a showroom shine on this one, just trying to get the board water-tight and the cans emptied so I can move on to surfboard-specific resins.
I sometimes tape some cling film over a nose or rail repair as a cheap vacume bag… without the vacume.
You need to pull the tape tight around the edges to pull the creases off the resin. Once it has gone off, and as long as you didnt use too much resin, the repair will be perfectly flat with barely any sanding needed to finish it.
If you dont get the creases out it is always a hassle sanding it flat again.
Hey jrandy. I am still not sure if you know that the ‘wax’ part of the wax paper is key. Surfacing agent is dissolved wax in styrene which allows the resin to cure to a sandable nature as described above by SammyA. Cling wrap may be good for shaping qcell in a repair during a ding repair but does not help in your situation. It also sounds like your wet spots may be from lack of stirring when the catalys was added or you scraped the bottom/sides of the bucket that did not have any catalyst. Once you have it sanded back the best you can it sounds like you want to do a second hotcoat. Good luck.
Polyester resin, as used in surfboard construction, is known as an “air inhibited” resin. That means exposure to air prevents a full cure. So, the styrene /wax surfacing agent simply creates a barrier to the air, since the dissolved wax is lighter than resin and floats to the surface. So technically, anything that prevents air contact will assist in curing. The trick with wax paper vs cling wrap is that the paper doesn’t wrinkle as easy, and it won’t stick to resin.
Just when I think I’m getting this stuff a new tidbit. I guess the wax paper would be easier to remove since the wax releases from the paper leaving wax residue on the resin. This residue would allow curing to continue after the wax paper has been removed. Thanks SammyA
Um, not really. Wax cannot be dissolved by resin alone. That’s why wax is mixed with styrene to make sanding agent. The styrene dissolves the wax, creating a medium for it to be mixed with resin.
Archives are saying 220 if your gloss coat is rough, 320 if it is good. I think I will try a hand block w/ 150 on the wax paper and see if get more to tear off before using the power sander.
Archives also produced a gloss recipe featuring a little bit of acetone int the mix. Since I have no styrene...
I tried again on two boards, two different cans of resin, not cross-mixed. Catalyzed at a hair over the 1.5% recommended and added 5% acetone. Poured the bucket on the board, quick flood with a 6" squeegee and a long-cross-long with the chip brush. Things went much better. I got a little waterfalling with the older resin and a few streaks from the brush going fast (!) but no whole-brush scars and sticky stuff like last time. Each board looks a bit different, supplier said one can of gloss was waxed heavy before I got it. They have been in the shop overnight at 75 degrees and seem to be doing fine. Outside temp was -1 F this morning.
Thanks for the advice recently and to those posting back in 2004, -J
PS Using Google to search by typing "swaylocks:gloss coat " w/o the quotes into the search bar.
I’ve put down a hot coat on my bottom and top and I have a few small spots where the hot coat created a “crater.” It didn’t seem to stick in these places. On the top, I just put another hot coat over these areas. What is creating them?