Hey guys, Just finished putting lam on a new board Friday. Now weather has gone cold for a few days and inlaws are in town for the Holiday. How long can I wait before hot coating? I placed a sheet of plastic over it to keep the dust off. I was concerned because the resin has cured for three days now. Is there a prep procedure when the lam coat has sat for a coupla days? I still have to do a light sand to knock the bottom lap strings down and then I was planning on a light baste coat on the bottom. I won’t get to it until next week now! Bummed. Also could someone make a stab at describing what the correct amount of cloth saturation looks like? My lams look like wet cloth, not super shiny, with the weave about half full but nicely coated. Seems light and strong to me. Kick time was 10 minutes and all went well. Just curious as usual. Thanks. Mike
The lam can sit for as long as you take. Lam resin will never dry hard and the exposed cloth weave provides both a tight chemical and physical bond for the hot coat when you get around to it. However, I’ve laid sheets of plastic over lammed boards and had the last vestiges of evaporating solvent partially stick the sheet to the board. Hope you make sure this doesn’t happen to you, by occasionally peeling the plastic from the board.
sounds like you have just the right amount of resin in your cloth. The weave should be plainly visible, and if you look very closely the space between each yarn or thread of glass should be about half full. If the space between the weave is empty, even though the yarn is fully saturated, you risk not having the hot coat fully penetrate, resulting in trapping bubbles in the weave. If you’ve laid on more resin, and the weave is somewhat obscured or not easily visible, no sweat! Consider lightly sanding, then polishing the hot coat without a finish coat. Think what the final product will be: fully saturated glass cloth with no exposure of the foam to water and only enough more resin on the lam to provide a good base for a shine or sanded coat.
Charlie, Thanks for the info. I felt it was right, but in pondering different aspects of all the things we do I needed a little reinforcement. Working with resin is enjoyable when things go well and frustrating when they don’t. I am using some Eastman resin (locally available) instead of Silmar and it has performed well so far. It is very catalyst sensitive though. 8cc’s to the quart @ 75 degrees gives me 10 to 12 minutes til kick. I have learned to be fast and efficient! Mike
My first “good glass job” was on a board where I had to wait a week as well… it allowed me to sand the laps smooth before my hotcoat. Just resist the urge to put your greasy paws all over it when you go into the garage every night to look at it (maybe that was just me). A quick wipe with acetone wouldn’t hurt.
what’s too long of a gel time for a lam? my resin gels. maybe 3 min.'s after i get everything smoothed out. on a longboard…
Like other said the lam can sit till you get to it. it is good to keep dust and other particulates and possible stains away, but this is more aesthics than structural. Wax paper is always nice to lay down if you are concerned about the plastic, also good to lay down on the contact points on your racks, and makes a good hand rest while touching up your laps. A quick wipe down with acetone and or denatured alcohol can never really hurt particular to rough areas. Look out for excessive moisture, you could get some glazing effect. Personally, I have always laminated, and fill coated all in one day (epoxy or polyester). With practice you will even be able to garner techiniques eliminating any grinding of laps. I do not do any production glassing so, it is easy to concentrate on one or a few boards if I need to. When, i shaped production we had glassing houses, so it is a different ball game for them. Outside of a climate control facility you will have to fight the weather. Also, there is nothing wrong with more than one fill coat. If your lamination was not as good as you think it should have been then squeegee on a thin layer of resin with surfacing agent and sand till your happy, then you can apply another thicker fill coat. One of the most common unnecessary practices i have seen or heard of first time glasser do is laminating each layer of glass separately. If you are going to glass a board with two layer on the deck, laminate them at the same time. Same with deck patches, insert the patch between or underneath the layers.
Rook! I have been diligently keeping my “greasy paws” off of it and I know exactly what you mean. A light wipe with acetone after some lap sanding should be all it needs. Laps were very smooth to begin with. This was due to diligence after a not so successful lam job on a previous board. Learning curve is exponetial when working with resin. I am working on doing the whole glass jobs in 4 hours or so due to time restraints. Smooth laps are essential to doing this. I decided to work on this board every chance I got…been a hectic schedule this week…working night shift and sleeping very little! Thanks guys! MLC