Built my first board, start to finish, all by myself this past weekend and now I’m in sanding hell. The major problem is this- my sandpaper keeps slagging like there is no tomorrow. By that I mean after about half a minute of sanding, the paper is totally clogged with junk and useless. Any tips on what’s going on wise Swaylockians?
One thought I had was that this was a hotcoat problem. I glassed the board in NYC this past weekend, and it was freezing. When I hotcoated the deck of my board (my first hotcoat), it took way too long to kick (~ 1 hour), so I knew there was going to be an issue. I moved on to the bottom, doubled the catalyst, and thought that went ok (kicked in about 20min). Worried about the deck, I went back the next day and applied a thin layer of hotcoat with more catalyst, and that too looked ok. Anyway I’m giving all this information because I’m wondering if the stuff clogging my sandpaper is improperly cured hotcoat.
I also want to say that Swaylocks made this board come together for me. I could never have built it without this site! Many thanks. Perhaps I’ll even put up a thread showing my new board in the coming days…
If you don’t want the board to get heavy with another hot coat. You can just put the board up for a while and the resin will eventually get hard. If it’s nice and dry and warm it’ll happen faster than in cool damp conditions. If your in a hurry you gotta shoot another hot coat.
Thanks Rich. As you know, it’s pretty cool and wet here in Santa Cruz, especially this weekend. How long am I looking at do you think? What is hard enough to sand anyway?
Having the surfacing agent separate from the resin in the can is pretty common. If it’s still tacky but appears to be fully cured, this may be what has happened. When you get a new can, shake it up to get it mixed. Shake again before each use. Never hurts to add a shot of extra surfacing agent before each batch just to make sure. The wax rises to the top and can get poured off with the first batch leaving the rest short on wax. I’ve also heard of guys messing up when pouring from a barrel to the retail sized cans - i.e. the label says one thing but the contents are something else. Overbrushing might remove the wax that has surfaced?
I’ll second the sanding agent thing. Use more. It should be like an eggshell more or less… a proper sanding coat - you should be able to drag your fingernail across the surface and not leave a scratch. It should take about an hour to hit this point. The surface will be slippery smooth basically.
John this is really interesting. I never heard about shaking the can of sanding resin first. I’ll definitely do that on the next go around. My hotcoat looks just like you say - it’s seems fully cured, but it’s still a bit tacky. Will sanding more even help this, or will it always be tacky if I don’t add another hotcoat? Even if I let it cure for a few days in warm temps, as Rich suggests?
Howzit adk, My experience with bad hot coats is limited to only 2 ( tried the UV ) but all I had to do was hand sand the tacky surface and the resin below will sand just fine. Aloha,Kokua
Right on Kokua. Right now I’ve got the board hanging out in my house and I’ve turned up the heat. The last round of hotcoat was on Monday morning, so I figure a few hours in the warmth and then I’ll bust my elbows sanding.
Another question for all you guys: how much surfacing agent would you add to resin? Both if it has none already (laminating resin) and if it has it already added (sanding resin) but just to be safe. Thanks!
get some wax paper and a hair dryer and apply let sit over night helep me a littlle one time I also use it on my laps before they cure while still tacky i apply it makes for an easier sandin of laps…I no it sounds stoopid but a roll of wax paper at the grocery stoe is like 3 bucks…and it works seals out air allowing full cure…p.s easy with the hair dryer
Someone who has lots of experience with Poly resin will have some other ideas I’m sure. Instead of painting another hot coat on the board you might squeege a real thin coat on with surfacing agent.
Here’s another trick that may work for you. Take a sponge with a scotchbrite pad on one side of it. Get yourself some 80 grit wet dry sandpaper and sand the whole board while lubricating the paper with water. You may be able to get the thing to the stage of being able to switch to dry sanding if you give it a good go with wet sanding and then let it cure in a warm dry place for a day. Even if it doesn’t work that fast at least you’ll be able to get an idea of where you need to work on the board when you go back after it.
Just ideas here. Final answers are allmost always impossible to come by.
I’ve had the same problem and done as Kokua suggests. Sand the heck out of the thing changing discs as they clog. Eventually it starts to look “normal” and you can gloss as usual. I’ve gone through a shitload of sanding discs on a badly hotcoated board.
If you havent already solved the problem then do this:
Find the smallest room in the house, open the window slightly and turn on a fan forced electric heater.
Let the room start warming while you find a spot for your board - even if it stands up against the wall (but lying flat as high in the room as possible is best. (I have used my laundry with the board on block on top of the ironing board).
Leave it over night…
One post cured board… will be ready to sand and will not clog nearly as easily… watch the clogs if your using an orbital or similar tho as they can cause scratches in the surface…