Still on my first board, which I've now glassed. Some general questions which would greatly help me progress (and not make the same mistakes on my next board):
1. Do you need to sand the board after glassing and before the hot coat? Or just purely after the hot coat?
2. Do you drill the holes for the fin plugs and leash after glassing but before the hot coat, or after the hot coat?
3. Is there anyway to prevent the board from getting stained when sanding after glassing? I'm using a Makita orbital sander. The stains are from the catalyst wax being sanded over...not all over, just in places...
4. Is it possible to use epoxy resin to glass a PU board? If so, what are the advantages? is the process the same? (My board is made of PU and used PU Resin + UV Catalyst for glassing)
1.only the laps on a PU and on epoxy its preference.
2.Depends on the system or leash plugs. some go under the glass some at the end.
3.You are not mixing your resin correctly or some other issue. Shouldnt have any staining issues. If you used UV for the Hotcoat did you just stick it out in the sun? If so you did it wrong you need to take it out for like 20-30 seconds and take it back inside for like ten minutes and then back in the sun for 5 minutes or so. Sounds like a bad uneven cure.
4,Yes, More durable board, process is the same/similar.
Every question you asked here is pretty easily searchable to get more clarity and info, The Box on the upper right is your friend.
I'm not an expert or a pro, but I'll answer to the best of my ability.
1) Not in all cases, but since you mention "catalyst wax", then in your case, yes. There should be no wax between coats of resin. Did you glass with gloss resin?
2) I build wood boards and install before glassing - ha! But on a foam board, I install after the hot coat, but before the gloss coat. I think it depends somewhat on which fin plug system you are using, I use probox and fins unlimited.
3) This one is kinda hard to answer, maybe posting some pics would help. I glass with epoxy, and haven't used poly in years, except for sometimes on a gloss coat. But again, I have to wonder why there is wax in your lam.
4) Yes, you can glass a PU board with epoxy. The advantages are less smell, easier cleanup, allegedly stronger more flexible lam coat. I use Resin Research epoxy, and like it.
Can you post some pics of your project? Its always helpful to have a visual to go along with a written explanation, especially when there are questions.
Thanks guys - ok I’ll provide a little more context.
I’ve laminated both bottom and deck, using about 1 Litre of poly resin + 10cc UV Cure Catalyst (on each side) - as I understand this is about right?
The problem I have is that I seemed to have omiited a very important step (yes, complete newbie error), in that I didn’t tape up and cover the other side of the board to allow to cut the laps after glassing…which means now I have a mess to sort out…I’m not worried too much as it’s my first board, and won’t make the same mistake on my next board (which I’ve already shaped).
I got the sander and sanded down the laps - initially I started with coarse sanding paper, but what I noticed was that the wax was getting stuck to the sanding paper in little chunks as I was sanding, and then that was sort of staining the laps (as in making the laps looks sort of dirty)…
Regarding “why I have wax in the lams” - well as I understand it’s the catalyst that has a wax agent in it, which allows it to be sanded later…in terms of was it cured evenly or not, I’m not really sure, it’s definitely cured (I glassed a few days ago), and yes I did put it in the sun but can’t remember exactly for how long…I thought you would just put it out in the sun until cured and then bring inside…
I will post pics of the board tomorrow, although they are pretty embarrasing
If I was to use epoxy resin for my next PU board instead, can I still use the UV catalyst in the same measures as I’ve used so far?
I haven’t done the hot coats yet.
Regarding fin systems, I’ll use FCS plugs - any recommendation on whether to drill the holes now or after the hot coats?
You should never have wax in your lamination coats. your hotcoat will not bond to it. i wouldn’t use a orbital sander to sand your laps of your lamination, your lamination will stay a little tacky and that is why you are getting that gum on your sand paper. just use a hard block with 60 grit. you could also use a grinder with 60 grit on a hard pad but i found that with the orbital it gums up a lot more than my grinder or hard block. As far as epoxy uv i dont think they make such a thing but i guess i could just be out of the loop. is your using fcs x-2 plugs you install post hotcoat.
Are you sure you put “wax” in the lam resin. catalyst(mekp or UV) should’nt have wax in it. If you buy “sufacing agent” that does have wax in it. lam resin is tacky so it gums up sandpaper. if you are using silane glass(it’ll look clear when laminated) then you do not have to cut lap. cutlaps are preferred on color in the lam and/or volan glass…purely for aesthetics.
Thanks heaps guys, yes perhaps it’s not wax and I had thought it was when I saw the resin gumming up on the sanding paper…
I might switch to epoxy for the next one and move away from poly resin…
i recon you just need to read up on sanding … absolute schoolboy error youll be fine with a tiny bit more understanding… and a whole lot of elbow grease…the orbital will not get you a flat board and to try leaves you a good chance of over sanding…get a hard flat block and hit the high spots after scuffing with the orbital. with your block use 60grit followed by 80 then the orbital lightly with 80-120-180- heavy going over should be fine now with 240. more then you need…my boards i leave at 180 as a fine sanded finnish is just slippery…
or buy a cheap small grinder and 4’’ sanding attathment with 80grit to be safe…kind of… be very careful and only LIGHTLY touch the high spots.VERY CAREFULLY! youll still want to block as i said above but you will halve your time.
I don’t understand why you are sanding a hotcoat with60 grit. If you can do a decent hot coat you can start with 100 even 120. also, I sand to 320. long strokes parallel to the stringer on bottom and rails for speed. don’t see any reason for leaving it at 180 besides being lazy and not wanting to finsh the job. I think it’d collect dirt and crap too with that rough of a finish.
see this kind of thing everywhere on here. simple misuderstandings/differeing of opinion.(heres some of my opinions)
1st reason as i mentioned going past 220 and the board is slippery.
boards for me i leave at 220 max as im not interested in keeping it pretty or showing anyone how shiny it is. once i slipped and hit my nose while duckdiving a new board.
selling a board sure 320…why not. first impressions yadda yadda…
im sure caymans first try will be far from pretty anyway. and the finer you go the more you see.
also i dont by into little scratches fighting/assisting gravity to the point of a humans weight on a board propelled by such a strong force which would easily break bones even at 1’ mush. so much carry on in the surfing industy…all salesmen and sheep. sorry for any offence taken just my opinion…
for any help from your finish id guess quite deep textured/purposely formed contours may help
sharkskin comes to mind…
some say a polish will suck to the water surface. again im not sold on my experience. i feel a difference but at high or low speed, positive or negative, i dont believe one could say…your line on the wave positioning of your weight on the shape/fins, shape of board/fins. positioning of fins sure big difference. even some would argue planing surface the riders weight and fins are the only real noticeable difference in speed.
the whole board? no way! 60grit just the lap before and after hot coat by hand and or cautiously with the orbital. and any high lumps of resin…remembering its his first glass job. there will be plenty.
ive never hand sanded a board id imagine itd take hours?
agian cayman EASY on the sanding you dont want to hit too much fiber! if you see any stop.
60 grit in our shop is only for rough shaping, In th sanding room we start with 100 and go up from there. If you you can start with 60 You are either A) putting way to much resin on B) taking way to much resin off C) got a really good deal on a bunch of 60 grit. D) All of the above.
To finish to 180 is only acceptable if you are going to gloss afterwards otherwise its a lazy manys finish.
Thanks guys - really helpful. Remember that I haven’t done the hot coat yet, just purely finished the laminating.
I’ve now sanded the laps with the orbital (yes resinkook, very lightly :-)) and then moved on to the sanding blocks #60, #80 etc etc to get an even surface.
I agree that once I do the hot coat, will not use the orbital at all and just purely do any sanding needed by hand…
Regarding elbow grease, yes I’m used to sanding the whole board by hand as I’ve shaped 3 boards already without a planer
Again, cheers for the comments and suggestions, will post pics of the first board (a.k.a. dog’s breakfast :-)) when done.
Resinkook You werent clear about the 60 SO I went off of what you said originally.
Its not being a critic, your first post without your clarifications was vague and left a lot to interpretation.
Even on the laps we dont use 60. We could but what we are doing works fine. Even on the rails I wouldnt touch them with 60 My sander starts rails at 150. The only reason to do 60 on rails IMHO is if you did a really sloppt hotcoat and there were tons of rips to level out. Otherwise not a chance. Our rails are usually pretty nice and require minimal sanding.
Even on the laps we dont use 60. We could but what we are doing works fine. Even on the rails I wouldnt touch them with 60 My sander starts rails at 150. The only reason to do 60 on rails IMHO is if you did a really sloppt hotcoat and there were tons of rips to level out. Otherwise not a chance. Our rails are usually pretty nice and require minimal sanding.
[/quote]
Cayman's doing his first glass job. I think its pretty safe to say he's not going to be performing at the level of a professional glassing shop LOL. I would think 60 grit is OK for the first time out the gate. Just don't sand thru the weave. Its OK with me anyway =)
