Spackling EPS

My first post. I’m a former avid surfer who got out of touch with it after joining the military. I live on the Gulf Coast of Florida which doesn’t lend itself to consistent waves. We do have great fishing and I have been interested in getting my own SUP after SUP and kayak fishing in the Keys. After seeing the prices of good fishing SUPs, I have decided to try my hand at making three for my wife, son and myself. They will be EPS / epoxy boards. I have been pouring over this site and Surfer Steve trying to learn as much as possible. The one thing that I have not been able to really get a definitive answer to is spackling on EPS foam. It seems to be a very divisive subject. Can anyone guide me as to the pros and cons?

Grumpygator,

I myself am on the gulf coast. Ive made 6 SUP’s so far with and without spackle. I believe it depends on your eps foam quality and finished product after sanding. The spackle is used to fill in gaps between eps beeds that sometimes show. Gives it a smooth filled finish. Also gives a bettee appearance if you’re leaving it as a clear finish. If you plan to paint with car paint or using pigmented resin, i dont think its needed. Most good SUP’s have car PPG paint over them.

Pros…What Bluefin says… fills the gaps between the EPS beads. If done right you get a lighter board… doesn’t really matter for a goat boat or a tanker.

Cons… most people do it wrong…read too much into it…and end up worse off…go off track somewhere…fail to listen to Resinhead, use concrete instead of lightweight spackle… ect…

…and…surfer steve? really??

And some use wood glue and cabocil. And that sux. haha

 

Where on the Gulf (if you don’t mind my asking)?

Sarasota

Yeah some use wood glue.  Ha!

Epoxy is expensive.  Light weight spackle is very cheap.  By using spackle you will use a lot less of the expensive epoxy.

thats why I tried using wood glue. 

Do you think tape will stick to it after sealing? Nope.

Back to using epoxy again.

 

Well I did try the custom stuff that Graphite Master sells and didn’t find it to be too much differant than plain old “liteweight” spackle.  So I have settled on Ace Hardware.  Lowel 

Red Devil Onetime Lightweight Spackle, thinned with distilled water. I tried thinning it with the Pledge (Future) floor finish and it smelled nice but seemed harder to sand, almost like it was balling up and catching on the paper or screen. Could just be me too, operator error.  I do like the Pledge for thinning acrylic paints.

Too much acrylic.  It balls up and is harder to sand.  The last “fast n Final” I bought was like that.  Was also too grey.  

Époxy resin, more weight but way more durability.
Spackle is a good way for low weight board. There is many way to seal foam each have their pro an con. I do lab and surfing test and facts are deeper resin go in foam heavier and durable are boards (with same glass schedule skin are stiffer, more dent and buckling résistant).

Hi all, cant resist to ask a few questions:

 

When i use the epoxy /microballoon/ cabosil slurry, i find it very hard to sand after curing.

Also the slurry sinks down a bit in the holes, when the consistency is good for applying a thin coat. When i mix it more like peanutbutter consistancy it stays level, but sanding is even harder, cause on the high spots there is nearly no spackle.

Do you apply two or more spackle coats? Do you use a different hardener and or specific resins?

I know most of my problems come from bad shaping skills, dings on the blank etc…

Also i cant find any of the lightweight spackles here in Germany, the only product i found was moltofill Modellierspachtel,

maybe someone got a hint?

I tried to mix my own lightweightspackle by mixing white  acrylic binder - something like gesso- with microballons.

It sands very good, but seems to be weak, and in deeper dents takes days to dry.

 

 

What JSPR is doing is NOT light weight spackle…not even close. yes there’s plenty of threads on Swaylock’s about slurry… good luck sanding that stuff…

DAP Fast and Final changed their formula…not the same…

Mr Resinhead told me to go to Sherwin-Willams paint store…Great guy that Resinhead…

Sherwin-Willams “Shrink-Free Spackling”… Green and black label. Thin with Distilled water. Just a little bit. Talk to Barry and he’ll tell you to focus on finishing the blank up really clean and no spackle…carry on

Stingray

Spot on Stingray. 

What stingray said.

I’ve only done one board each way (1 w/Dap FastnFinal spackle, 1 w/epoxy slurry), so take my limited EPS experience for what it is.  As lemat said, sealing can be accomplished many ways, each with pros and cons.  However, I feel that for the hobbyist, lightweight spackle - properly used on a well-finished blank - is the wisest choice.  Greg Loehr himself has said as much on multiple occasions.

To Gator (the OP), watch your inbox.  I’ll be shooting you a PM soon as I’m done with the flu. I’m right around the corner from you.

Yes.  Liteweight spackle thinned slightly.  Use a plastic squeegee to spread.  Fill the voids squeegee off the excess.  Dry overnite and screen with a wore out piece of 220 screen(gauze as you say in Euro speak.  Makes a nice surface.  Paired with a pastel acrylic paint  hard to tell from a Poly blank.  Just like Greg L or Stretch would do it.

I make about 50 with spackel from polyfilla in Europe and about 70 with époxy base slurry. For both you must squegge out all over with a stiff squegge so only scuff needed

I’ve found Fast and Final turns to mush around dings.

I’ve started using Zinsser paint/cabosil as recommended here on Sways. Fills well. Sands nice. Lightish. Yet to glass the board I’ve used it on.