Amazing forum, can’t wait to start shaping my first board. Props to everyone. On to the question… If a ding is repaired with a qcell/sanding poly resin mix and sanded back even to the original glossy finish, is it water tight? Or should a hot/glossy coat be applied in addition to the qcell/sanding resin mix? The reason why I ask is, I just purchased a 9’0" Local Motion longboard at a garage sale for $75 (could not believe it, asked the woman if she wanted more and she said no, hehe). The original owner fixed a couple small (no bigger than 2"X2") dings with the qcell/sanding resin mix, sanded them and called it a day. I couldn’t resist taking it out the past couple days in LBI before/after work but began thinking about this last night laying in bed and it’s been eating me since, so any insight is appreciated.
no… its not water tight. i tried that aproach once and it wasnt pretty. you need to apply a fiberglass patch to it and then hot coat over that (assuming you’ve filled the dings)… there are tons of resources on ding repair… check out “resources” section and type in “ding repair” in search window. sounds like a good find though… just make sure there arent any hirline cracks that could let water in. if it was me, i’d fill in all dings, patch them all, hot coat them, then give the board a good sanding and re-hotcoat it to make sure you got all the cracks…specially voids near fin boxes/plugs if it has them.
Welcome to swaylocks… Best way to get good and plentiful responses… Post a PIC. We love pics.
Actually, Devil, that repair could be perfectly fine. All depends if they hollowed out some of the foam on the backside of the glass or not. I’ve done plenty of repairs like this, with stuff I’ve mixed up and with Solarez, straight outta the tube (same idea). The results are very good as long as you take out the foam around the periphery of the hole on the underside of the lam and make sure you rough it up well and get good saturation. If you can see a little halo underneath the lam around the repair that indicates it’s filled with resin, you’ll be fine. Otherwise, look for little cracks between the repair and the lam; if you see any of these, you may want to go back at it. Should add that a layer of glass does nothing for the water-tightness of a board…it’s the filler layer of resin that takes care of that. At the end of it, it’s a 75$ board (and a log ;)); surf it.
i usually put on the fiberglass to prevent breaking out the chunck i replaced… but then again im an epoxy guy… my filler is spakle… I guess you’re right since its a poly repair not epoxy. still doesnt hurt to check resources section though
My experience is that the resin mix is no more rugged than is resin alone: smack it against something and it can and will crack. The effects of heat and cold ( expansion and contraction of the patch vs the original ) could leak too.
So, what I do is glass over it, every time, unless it’s the size of a pencil eraser. And sometimes even then.
hope that’s of use
doc…
I couldn’t agree more with Doc.
The thing is, filler is a solid chunk and doesn’t flex or compress like the glass on the rest of the board. Filler is bad about cracking around the edge where filler meets the old glass. Especially from pressure dents next to the filler on rails and such from duck diving, etc., or bumping a filled nose or tail against something. Those small hairline cracks or seperations usually leak and the water damages your foam and causes it to break down and turn brown – only this is happening deeper inside where you can’t see it, and you eventually have to cut out the filler and bad foam and repair a larger area. Like Doc, I always glass over filler. Now if you sand through the glass on the tip of a filled nose or tail, that doesn’t matter as long as it’s over the filler. But I’m always very careful to make sure the glass patch is good over the area where filler meets board.
Just my .02 HTH
How it goes depends on the ratio of Qcell to resin. A thin batch will be rather fluid, penetrate well but be harder (relatively) to sand. A thick batch will be lighter, easier to shape.
I use Qcell to patch in the few times when I have a ding that’s big enough to need it. I’m happy to leave it uncoated, but I usually mix a pretty light batch with lam resin and catalyst, then after shaping it, I lightly brush a finish coat of straight resin over it.
I think a Qcell patch will be watertight, most times. To test, ride the board a couple times then leave the patch area in the sun and see if any water oozes out, or whether a white salt crust appears at the ding site. If you see either, you’re not watertight. The Qcell mix alone is watertight, but a large mass, set off quickly, is likely to crack.
Overall and to be sure, sand with 60 grit and brush a finish coat over it, but I wouldn’t be too anxious about it. If the last guy could get it to shine, he likely had a finish coat on it.
Come on guys! It may be water tight but it has no stringth at all. The Qcell is only used to fill a hole. You have to put glass over it or it will, Crack, split, fall out, or be damaged by just looking at it wrong. Sand down the qcell, to just below the glass on the undamaged part of the board. Make sure you feather the good glass back at least 1/4 inch I like 3/8 or more. Lay a piece of 4 oz glass over the repair. Glass it down with sanding resin. Just as it starts to kick take a blade to it and clean off the excess resin. Sand it and apply gloss resin. Sand it down and polish it out. A $75 board is still a surfboard and should be treated right. Fix it right and surf it hard.
There are several materials that flat-out perform qcell or good ol’ chopped fiberglass…
…you guys aren’t doin’ yer homework!
…Herb
…On to the question… If a ding is repaired with a qcell/sanding poly resin mix and sanded back even to the original glossy finish, is it water tight? Or should a hot/glossy coat be applied in addition to the qcell/sanding resin mix? The reason why I ask is, I just purchased a 9’0" Local Motion longboard at a garage sale for $75 … The original owner fixed a couple small (no bigger than 2"X2") dings with the qcell/sanding resin mix, sanded them and called it a day. …
Well Herb, we could’ve suggested that magic wand that transforms pre-existing filled repairs to a better filler, process, and overall condition, but that might have sounded a little sarcastic.
So what do you suggest he do Herb? I have my notepad ready . . . . . . .
{edit beer induced response} When a customer asks for q-cell, that’s what he gets. Otherwise he tends to think you’re trying talk him into something else to increase your own profit margin. …or something. {/edit}
Neither being Herb or Merlin…
glass over 'em. Sand, gloss/hotcoat, call it a day.
Beer…no, ale-induced response.
Glass-fibers in filler=misery in sanding and in long-term durability. Q-cell or aerosil, wayull, nice enough for the nonce, though if they come up with a cures-to-white Gorilla Glue then I’ll be all over it, 'til then I will fake it with Aerosil/Cabosil cos it’s cheap and easy.
And on that note, time for a coffee- with rum. Beer-induced is all well and good, my friend, but why not aspire to more, no?
doc…
I think what Herb is talking about is diper filling? Am I right Herb? Or maybe cutting out the ding and replacing it with foam. That is by far the best.
Most or all fillers including chopped fiberglass weaken the repair.
…Bagman was in the ballpark when he stated ,“foam plug”…one-up/ better would be casting your own foam…but that’s a long story and it’s been covered here in the past a few times.
…Polymer,better known as “diaper filler” is use for several things including firefighting,and movie snow…Polymer does just what I stated in the past message,“flat-out performs”.
…Aerocell can be “out-flanked” by using good ol bleached flour and/or corn starch.Rice cerel for babies works too!.
+++++All the fillers/thickeners I have stated here are cheaper by volume,signifigantly stronger by volume/weight and easier to access/obtain than the more commercial fiberglass fillers…Herb.
And if your resin gets too hot you will have that fresh baked smell! Either that or a stinky diaper aroma!
The main thing that weakens a repair is the lack of fabric covering it. Make sure you put some on.