Hot Coat

General Discussion
1

I have just hotcoated my deck with RR Epoxy.

After glassing with 4oz twill weave glass, I left the epoxy to cure for about 1 hr at about 14 deg c, (when it was at the tacky stage) then  applied slightly heated epoxy.

Both the glass coat and hot coat had the correct amount of addative ‘F’, and I used a new, clean brush. The glass coat was fine, no problems.

Fish eyes everywhere, very annoyed.

Any ideas?

 

2

Contamination.     Have seen it with poly, when a tape manufacturer altered their adhesive formula.   Lots of possible sources.   Usual suspects, wax, silicone, oil.     WD 40, sprayed anywhere within 50 feet, could migrate to the hotcoat.

3

…I think that you d checked that all was clean, included your hands, etc

but 14C is a resin killer for almost all the resins

and you have luck that no moisture (whiteness) grabbed in…

4

Thanks

So what would you say is a minimum temperature to hotcoat in?

I guessed at 14 deg C, but I Just checked with a thermometer, it is nearer 18 deg c.

I wore gloves, hoovered workshop well before I glassed and let the dust settle for at least 4 hrs, and have used no lubricants, sprays etc in workshop recently.As I said, the glass coat looked fine.

I am glassing and hotcoating the base tomorrow, hoping for better results!

How do i know when to apply the hotcoat?

 

thanks

 

Gary

5

my epoxy have a workingtemp. from 10 deg. c - 25 deg. c.

i would check the archive, you will find a lot more informations about fish eyes

6

My first RR hotcoat looked similar. On the next board I tried two changes: First I tried creating a "clean room" out of drip cloth, to reduce draft and incoming dust particles. Surprisingly, no big change. But then I also strained the resin through a filter, and that removed 95% of those bumps! A huge improvement.

Still it's not perfect, and I think part of the remaining problem in my case is airbubbles - maybe from stirring the resin - that rise to the surface while the hotcoat cures. I can clearly see these appear and pop while the hotcoat cures. Maybe a higher resin or board temperature could help reduce viscosity and airbubbles, not sure. I also read somewhere that Greg Loehr now recommends the 2040 resin for glosscoats. That resin has lower viscosity and I think it should also help with the bubbles.

Anyway, straining the resin made a huge difference. I used a cheap paper filter from fiberglass supply, but I suspect a panty house would do just fine.

Let us know how you progress, maybe with input form others we can arrive at the perfect procedure. There is some conflicting advice in the archives when it comes to preparing the surface. I concluded in the end that cleaning the surface with alcohol or similar is not recommended. So after finesanding I only use a dry brush to dust off the board. Any remaining particles from the sanding seem to become invisible once the hotcoat is applied.

7

Hey Horn, i had/have the same problem. I have little freckles in my coat. I dont know, if its because iam used one room for shaping and glassing? The next time i will move in my garage to glass the board. Also i want to try the filter method, what kind of filter do you use?

Here is my thread about that topic, you can also read the resinhead answer, may be it will help you!

http://www2.swaylocks.com/forums/coating-and-pinline

8

Hi Christoph,

I got my filter from http://www.fiberglasssupply.com/Product_Catalog/LaminatingTools/laminatingtools.html for 29 cents - see item #T17-8974: "Paint Strainer, fine mesh, disposable paper filter, for removing lint and lumps. A must for varnish work, glossing surfboards or sailboards. "  There's a picture of it.

I still don't have perfect results, but the filter helped a lot.

I filtered the resin after mixing with hardener and aditive F. It took quite a while to run the whole hotcoat amount through this particular filter, so it may be better filter the ingredients seperately before mixing, or to use a slightly coarser filter. Others here on swaylocks have recommended filtering through pantyhose.

9

really pentyhose??:) I thought to use a coffee filter, would this work?

10

Could be coming from the bucket, too…

11

"I have just hotcoated my deck with RR Epoxy.

After glassing with 4oz twill weave glass, I left the epoxy to cure for about 1 hr at about 14 deg c, (when it was at the tacky stage) then  applied slightly heated epoxy.

Both the glass coat and hot coat had the correct amount of addative 'F', and I used a new, clean brush. The glass coat was fine, no problems.

Fish eyes everywhere, very annoyed.

Any ideas?"

Let's start with temp in your shop...A quick internet search tells me that 14 degrees C equals 57.2 degrees F......(very cold for RR glassing)

Resin Research works best at  around 75 degrees F (23.88 C).....Your workshop is way too cold to be working with RR and a one hour cure time is not long enough at 14 degrees C......There's other problems that may go away when you get some warm weather.......At this point you need to wait about one week and then power sand......Bring the board into the house so it can warm up and cure.....

12

GaryB wrote: I guessed at 14 deg C, but I Just checked with a thermometer, it is nearer 18 deg c.

 

13

I glassed and hotcoated the base of my board today. Good results, almost perfect.

2 things different:

Summer came back to UK, and I did the job at mid-day.Temperature was at around 21 deg C in workshop.

When I glassed, I used much less epoxy - only just enough to wet out the glass, and I hotcoated as soon as the glass could not move, ie sooner than I did yesterday for the deck.

One mistake I did make, after glassing I put a convection heater on. This caused the glass to balloon up. Luckily I was able to recover the situation.

Obvious when I think, should have heated workshop BEFORE glassing.

 

 

14

How much Epoxy do you used?

15

Hiya Christoph

I did not record how much resin I used, but I brushed the resin onto the board as thin as possible, then unrolled the 4oz twill cloth over the resin, then squeezeed the resin through the cloth. I made sure there was no excess resin laying on the cloth, but that it was totally wetted. I needed to make up a further very small mix (around 20g total)to do the rails.

Hope this helps.

I will post a picture of the finished board in next few days.

 

16

Yeah, i cant wait to see some pics, i will start tomorrow to coat my board if will find the paint strainer.

17

ok so 18c is closer to 64f?  It's still too cold.  Epoxy is more tempermental than poly. Get you room to 70 degrees minimum or 21c.  Then get you epoxy in the micro wave to 75 degrees.

 

Also be careful what you put your epoxy in...then micro wave it.  Why...well sometimes we use those cheepo dixie cup or wax paper cups. When you micro them, they release the shitty wax coating from the cup into the epoxy....blamo instant contamination.  Use glass or thick microwave proof plastic.  And microwaves cook form the outside in, so the container will get a lot hotter than the stuff inside in a hurry.

You board looks ok, epoxy sands a lot faster than poly anyway. You looking at an additional 10 minutes of sanding? Big deal?  Sanding's fun!

18

Yea, you gotta love sanding, been doing it all morning.

Anyway, here it is, almost finished. Still a bit of 1200 wet n dry to be doing, b ut that can wait.

 

More on:

http://s529.photobucket.com/albums/dd338/garretstowngary/Homemade%20Boards/

19

looks pretty cool! i like it