Hey, besides a few untactful posts, I’m new to the forum and have a question. I’ve done about ten boards thus far.
A batch of glassing resin got recently destroyed at home. I’m wondering if I can use my sanding resin for the base resin coat. I’m guessing this will make sanding down the laps easier, if needed, but I don’t know whether using the sanding resin will somehow ruin the bond of the fiberglass to the foam. Any advice?
Thanks.
I always use Resin Research epoxy resin for lam and hot coats, then gloss with poly. So I don't know the answer, but what I wanted to say is - doesn't everyone use the same resin for glassing as for hot coating? I never knew there was a "glassing resin" and a "sanding resin".
For Polyesteer resin there is Laminating resin which is used with fiberglass cloth for laminating. It stays tacky so that subsequent coats will adhere. Then there is sanding resin used for the hotcoat. Sanding or hotcoat resin is made by adding a surfacing agent to the resin. This allows the hotcoat to be sanded. If you use sanding resin for laminating and then hotcoat with sanding resin you will most likly have adhesion problems between those two coats. You might even have adhesion problems between your laps. Sanding resin does not adhere well to sanding resin unless it has been sanded. You can't sand a whole board that has been lammed with sanding resin well enough to insure good adhesion of your hotcoat. Suffice to say such a procedure is not worth the risk of failure
Pollyester laminating resin-------Usually Silmar 249 Polyester Sanding/Hotcoat Resin----------Silmar 249 with additive (ie surfacing agent) Purchased pre-packaged or you can by surfacing agent and add it yourself Polyester Gloss Resin --------Usually Reichold(737 i think?) Also UV can be bought both pre-packaged or add UV powder yourself for both of the above mentioned Silmar 249 Lam and Hotcoat. For gloss most everybody sticks to Catalyzed Reichold. I tried UV gloss back in the mid 90's with poor results. I love UV for lam and hotcoat, but would stick to traditional Reichold for gloss.
Thanks for the help. I meant “laminating resin,” not glossing resin. But your response was helpful, Huckleberry. Mcding, that answers my question on why I can’t just use sanding resin. Thanks a lot.
You guys have a good one.
heres a production technique that you could utilize to use up some of that sanding resin. glass bottom with laminating resin. then glass the deck with sanding resin and lay your deck hotcoat with sanding resin before the deck lamination fully goes off. obviously you have to time this right so that the lamination is not too wet and moves around when you brush the hotcoat and not too hard so that the hotcoat resin will not bond to the lamination. this trick makes it easy to sand the laps before the bottom hotcoat. but you still need some lam resin for the bottom........
by the way, sanding resin is just laminating resin with a wax/styrene additive. easiest thing to do is to buy lam resin only and make sure you always have a pint/quart of the additive laying around. then you always have what you need......
Typical polyester resin is known as an “air inhibited” resin. This means that exposure to air will retard the curing process. The styrene/wax additive rises to the surface in a batch that has been catalyzed. This forms a wax film which allows the resin to harden fully.
So, if you did a lam with sanding resin then applied a hot coat before the wax rises and forms that film, you should get proper adhesion between coats.
We often see folks post about about hot coats that stay tacky and are difficult to sand. This is most often due to over-brushing. Once the chemical process reaches a certain point the wax would normally rise to the surface. If you keep brushing you disturb that surface film and the batch will not harden properly. A trick I use for small areas that remain tacky is to lay wax paper on them. Expose to sunlight to accelerate the process and it will often cure all the way.
It is always best to buy straight lam resin and add the sanding agent as needed. This avoids being stuck with the wrong stuff for the job.
SammyA is right; Always better to buy lam resin and add surfacing agent. That way you don't get stuck with sanding resin when you have nothing to use it on. I haven't bought sanding resin pre-packaged in years. Best bet is to always buy Silmar Lam and add surfacing agent to make sanding resin when you need it. Buying lam gives you more options.
I also believe that lam resin has a longer shelf life than sanding resin. It may be due to the higher styrene content from the surfacing agent.
Anyone else find this to be the case?
Howzit Sammy and grasshopper,I second that and in my shop there was only laminating and glossing resin plus SA and Styrene. Aloha,Kokua
…oh yeah?, well, tell me what shops do that so I would not go there…
laminate the deck layers with sanding resin is a very bad technique because a non proper adhesion between layers due to “floating” meanwhile wax rise up
gaining also in tiny bubbles
Did Don Ho ever work as a laminator?
…sometimes music do not put money into the pockets (I know about it, by the way)
yesterday I was humming “Gung ho for Don Ho” by Slacktone
i was under the impression that if you laminate with sanding resin that the board gets pressure dents alot essier and is more likely to delam
or is that just a mith