Save that dust!

[JCNailen]

This weekend I have done nothing to my project but fill holes. With the rub rail off, there were so many holes to fill. And, on the first day I removed every spec of hardware from the entire boat. So, yeah, I had some holes.

I wanted to fill them with epoxy, but that was getting expensive, and messy. So I tried resin. That worked really well and dried fast and hard. I was able to sand to a fine finish. But I was having trouble with vertical surface holes. That's when I remembered "wood flour". I mixed up 2 oz of resin and dumped in 1/2 cup of sanding dust from my collection bag on the sander. It wasn't wood dust, it was dust from sanding fiberglass.

I whipped it up into a paste and applied/filled the holes with popsicle sticks. The additive added about 15 minutes of working time before turning into rock, but exteded the full cure time by a few hours, not to mention it is 97% humidity down here right now.

So, from now on I will be collecting my dust rather than throwing it away!

 

[reelfishin]

Re: Save that dust!

I've done the same but keep in mind a good part of that dust is ground resin too, not strength adding fibers. Ground pure glass works better if you need strength but if your just filling holes and cosmetic voids that works great.

 

[JCNailen]

Re: Save that dust!

I've done the same but keep in mind a good part of that dust is ground resin too, not strength adding fibers. Ground pure glass works better if you need strength but if your just filling holes and cosmetic voids that works great.

Very good, and thanks for pointing that out. Yes, I was just mixing a resin "putty" for filling screw holes.

 

[Mark42]

Re: Save that dust!

.... I mixed up 2 oz of resin and dumped in 1/2 cup of sanding dust from my collection bag on the sander. It wasn't wood dust, it was dust from sanding fiberglass.

I whipped it up into a paste and applied/filled the holes with popsicle sticks. The additive added about 15 minutes of working time before turning into rock, but exteded the full cure time by a few hours, not to mention it is 97% humidity down here right now.

So, from now on I will be collecting my dust rather than throwing it away!

OMG, you know that will cause your boat to explode into a million pieces the first time it hits the water!

Ahhh, I've done the same. And you are right, any time a thickener is added to the mix, it does extend the cure time. At least that is my experience.

In a pinch, you can use cooking flour too. Works just as well as wood flour, and it has held up great in the salt for years.

 

[erikgreen]

Re: Save that dust!

Collecting your own grinding dust is a nice recycling measure, and it makes a decent filler in a pinch.

A couple things to watch out for, though: It can contain or later absorb moisture. You wouldn't think very much, but it can be enough to affect the strength of your glass. It can also contain particles of abrasive, grease, wax, glue.. basically a lot of stuff that you may or may not want in your final putty.

Considering that wood flour costs about $5 a pound (which is a lot) it's not a huge savings, but I guess if you don't use it often or much...

Erik

 

[Utahboatnut]

Re: Save that dust!

I have also used CSM or even cloth ground to dust in an old coffee bean grinder, seems to work pretty well in a bind or to just make a few small repairs.

 

[erikgreen]

Re: Save that dust!

Great idea, just be careful to control the dust from it, and always wear a mask when you are near the grinder if it's open. Same risks as grinding glass with resin, except it tosses even more bad stuff into the air :\

Not to be negative or anything, just trying to share some caution.

Erik

 

[JCNailen]

Re: Save that dust!

Thanks Erik. I always try to be safe. I had to get a new respirator though. I learned that those paper filters aren't really worth much.