Is Silmar 249A "Laminating resing?"

Is Silmar 249A “Laminating resing?”

I have been buying it for the past few years and repairing beater boards.  I use cloth and Cabosil when needed, also. 

I just heard of styrene monomer, aka, sanding agent, but I’ve never used it.  

I simply mix MEKP and resin, apply, sand, and when it dries, everything seems ok.

Am I missing something?  I keep reading that “you can’t sand laminating resin and you need to add styrene monomer.”  Yet my repairs all seem ok.  Thanks!

Hi; yes; you perceive the repair as no tacky due to would be small so can be sanded ok.

However I must say that your repairs are not good as you say. The resin is a glue; the shell of the surfboards is reinforced plastic; hence the fibers. The ideal is to keep the reinforcemnet at more than 50% but that is not possible with hand lay ups; but you put only resin so you ratio is 0%. You mention that you use cloth “when is needed…” always is needed; do not listen to many guys saying that for small repairs is not necessary. Again; resin is a glue. You need to sand (do not use a cutter) just sand until almost the foam then proceed like you are doing all the board glass again. Do that always. All the steps. Do not do like a crappy repair guy that only put resin and then sand just ruining a new board.

If you have a hole you NEED to use the core material; always; normally polyurethane foam (get a piece of the side bones with a shaper). That is glued with resin and aerosil (with a tiny bit of white pigment only in the underside) cut almost like the hole then push it inside then sand it a bit to feather the edges etc (previously you needed to sand the glass besides to almost the foam.

When you have all that depends on the style of the board, you just apply a very thin coat of resin and aerosil with pigment to match (very very little pigment; mostly white) that is to level with the rest of the sanded glass besides and to provide a smooth surface; but again, sometimes you do not need that step.

Glass as a surfboard: lamination + hot coat + finish coat (gloss coat or spray coat)

Please do the things right, try to keep this labor the best as possible do not continue with the crap like many many around the World, that do not know anything and just ruin boards.

 

Thanks for all those details, Reverb.  So what is 249A?  Is it the laminating resin, and I therefore need to buy the wax additive, mix it with 249A, and use that as the final coat?

Hi; I responded in the other comment “yes”. You can make hot coat resin and also use that for the gloss. The gloss resin actually is more brittle but harder so you can polish it with finer grits. Most parts of the World do not use gloss resin but hot coat resin; so as you say laminating resing plus styrene monomere and wax (paraffin) disolved or just buy the product just ready.

If you use the ready product, add 5% to the resin (for example 1kg resin 50cc of the ready product)

This is great info, I appreciate your help.  I understand and will try to buy the ready made hotcoat resing and gloss resin, to make things easy.

No one ever taught how to work with resin & cloth…I just read on Swaylock’s and watched Youtube. I have two old longboards on which I may sand down my old repairs and try again with pieces of foam, cloth and the three different versions of resins.

I view these two old boards as a way to practice until I can do quality work.  Because in several months I have two new custom Phillips arriving that I want to be able to fix myself when dings happen.  New beautiful boards…I want to be able to fix them well.  

Thanks again :slight_smile:

Silmar 249A,  249OB, 249OB 3,  all laminating Polyester resin and all from the same 249A base.  Add MEK Catalyst.  Add Styrene Wax Solution to make Sanding Resin (Hotcoat).  Add UV Powder to make “Solar Rez”.  Reichold Gloss Resin.  A completely different animal that can be “doctored” to personal preference for ease of use.  Intended to be Wet Sanded and rubbed out with compound and polish or just good ol’ #2 Fiberglass polish.

Styrene monomer by itself is not sanding agent. Properly called surfacing agent, you are thinking of wax dissolved in styrene.
If the resin you buy dries hard and can be sanded with ease, it already has SA in it. Lam resin stays tacky.

294A does not have the blue optical brightner tint in it. 249B is the same resin but includes the optical brightener.

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