Favorite Filler Recipes, Please

Would anyone care to share their favorite filler recipe for epoxy?
I am looking for the strongest filler that still has good sanding properties.
This will be used over a balsa core to fill in the cracks in a Glass/balsa/glass layup.
Thanks,
Rob

 

I use the shavings and long-stranded particles from wood-working operations, alloyed with sawdust and its brothers.
Works good, and recycles stuff.
Colour is usually nice too, leaving a pleasant finish if varnishing afterwards.

For less aesthetic joints, or when working in materials not from trees, I like glass bead media from shotblast or beadblasting jobs.
Tough as hell: hard though, not so easy to sand.

 

add cabosil and micro ballons with some milled fiber , more micro ballons if your going to sand, if its for finshing leave out the milled fiber, some people will use anything to thicken it up, talc is often used wood flour, even flour for bread has been used anything can be used the dust off the floor but if you want quality use quality products they are cheaper in the long run

 

REzin heads in Miami used to use the ply saw dust from their core material.

 

the resin heads up here in canada dry out the moose crap in the sun and grind it down into powder never tried it myself

 

thats the secret ingredient in Tim Hortons Donut glaze

 

thats what i taste every morning ,

 

Cotton flocking is the strongest of the milled fiber fillers that is also easy to sand. Glass, carbon, and Kevlar are all available but are all hard to sand, Kevlar being the worst.

Jimbo

 

If your only using it as a fairing compound [ BOG] why would you want it structual???
Surely Qcells and epoxy is good enough, used it on most of the boats i've worked on including my own.
Cheap, light and easy to sand.

Dave

 

Catmando2,
It seems to me that although it is for fairing, I would want to take advantage of the chance to add strength. I must admit, though, with a Tim Hortons just down the street, I am tempted to get a dozen Canadian maples, squeeze out the filling, scrape off the frosting, and just start spreading!

 

No more filler for me in 90 % of cases I have found what I need ready in a can, only need to mix homebrew once a month nowadays.

I have tried many home made and over the counter fillers with great success and some failures over the years.

Nowadays im a bit lazy and for the last 5 years have used mostly nothing but Hempel’s ProFiller when fairing is needed with Epoxy, over all the stuff is easy and stands up good. For fun try spreading 1-2 mm of it on a wax glass or a sheet of PE and after it has cured bend it, along with any other filler you can imagine as a test, you’ll be surprised. At a 112 Euros for 5 litters its not eaven too expensive.

Hempel ProFiller 35370
Hempel ProFiller 35370 is a two component lightweight solvent free epoxy filler.
When fully cured is resistant to water, aliphatic hydrocarbons, and related products.
Can be applied in thick coats up to approximately 12mm without runs and sags. As a filler and fairing compound, especially suitable for profiling large areas and detailed fairing where structural strength is important.
It can be used on most primed substrates, above and below the waterline

 

Fine on small project i'm sure . Reckon it would cost too much on my sized project[see gallery] and whats a "Timm Hortons and squeeze the filling out of a couple of maples mean...etc, etc "mean???????

I'm in Australia,

Dave

 

tim hortons is a chain of coffee shops in canada maples a doughtnut, want to make money open a chain in aus , the stuffs more addicting than crack cocaine

 

I've mixed up several batches of filler for my home boat project, and I've had some problems. I'm filling a few hundred screw holes I made in the transom (curved transom that I'm adding layers of marine ply to strengthen it). I've got epoxy resin (3:1 mix I bought at the big fiberglass supply house), milled fibers (1/32 inch) and cabosil. I figured I want it real strong, so I mixed in about 1 part by volume epoxy, 2 parts by volume of milled fibers. This mix sagged a lot on the vertical transom, so I added cabosil until I had a stiff enuf mix to not sag. This stuff was really hard to spread - it was a bit dry so it didnt want to stick well, and it didn't spread to a smooth surface with the plastic spreaders. I mixed a bit more epoxy and added it in and got it to work, but I had a hard time getting just the right amount of epoxy in the mix - too much and I had sags, too little and it had the consistency of a two day old cow patty. Any suggestions? I want the milled fibers for strength, don't want to use floor sweepings. I,ve got a 50# bag of talc - what does it do for a mixture? Don't want to compromise waterproofness of epoxy either cause my transom looks similar to my wife's spagetti strainer.

 

it be cheaper just to buy a can of epoxy marine filler, you dont want the mix to dry. add less milled fiber to the mix, and more cabosil