"PB" Components

[cyber]

Hi All

I have "OOPS" original PB recipe, just a quick question.
I want to use it to 'fillet' (I think that's the correct term??)
the 3 edges of my new transom. It calls for resin, cabosil,
and 'milled fibers'. I have a few scraps of 1.5 oz. mat left
over from wrapping the transom, can I just cut that up w/
scissors and use it as milled fiber?? And if so, how fine
do i need to chop it up??

Thanx again!! Bill.
P.S.: I'll do an update soon w/ more pics (84 Thundercraft Resto)

 

[Friscoboater]

Re: "PB" Components

Buy it in a can because you need alot of it to get strength from what I have found. It would take a a while to cut up strand, but you could.

 

[ondarvr]

Re: "PB" Components

Milled fibers are very short (almost a powder) and will make a smoother putty than the longer fibers from cut up CSM. Longer fibers will be stronger, just a little tougher to work with, in the end its up to you because it won't make a huge difference either way.

 

[cyber]

Re: "PB" Components

OK, I think I'll try cutting up the scrap mat for this
phase. I don't need a whole lot as I'm only using it
for the bottom edge and the 2 side edges. I intend
to use the PL Premium and bolts through the bilge
& splashwell drains as well as the stern eye holes
on either side. I'l also rig up some of those fancy
clamps I saw in another thread.

Thanx for the replies guys, I'll try with the chopped
up 1.5 oz mat scraps 1st, and if that doesn't work
to my satisfaction, I'll make the trip back to the
marine supplier and pick up some actual 'milled fiber'.
I'll probably want the smoother look when it comes
time for me to fillet the edges of the deck.

 

[cyber]

Re: "PB" Components

OK, so I decide that since I haven't been cutting any
corners so far on this project, why would I start now??!!

So I went to the supplier and bought the actual "milled fibers".
It came in a 1 liter container (is this stuff ever heavy!!), same
as the cabosil did (it's light as a feather!!).

So my next question is (I know, guess I should've asked at
the supply store, but I sent my wife to pick it up since it's close
to her work) what is the "formula" for mixing these
3 components together. Is it equal parts all, or something
much different?? I seem to recall the guy telling me
to not be too generous w/ the cabosil??

I guess I could mix up a fair amount of it and then use smaller
portions at a time by adding hardener only to the smaller amount??

Thanx again!! Bill.

 

[rickryder]

Re: "PB" Components

There is no precise formula that I have found.... What I did was 2 quarts of resin and added cabosil until it started to stiffen up to about the consistency of pancake batter then added milled fibers until it was thick like peanut butter. I add the hardener after the cabosil and mix with the drill and paint mixer,then add fibers and mix with a paint stirrer,kinda fold it in.... seems when the first time I mixed with the mixer it became stringy and mixing by hand didn't have that effect.

mekp should be 1.5-2%

 

[bartborchardt]

Re: "PB" Components

Your post made me think of how helpful it would be to have a sticky in "How To's and Other Great Information" about the measurements (ratios) of epoxy, size of fiberglass, how much fiberglass, fillets, etc. for redoing a transom, floor and whatever else. I know it would be helpful to me and probably a lot of new people on here.

 

[P3FE]

Re: "PB" Components

I know this may sound like a stupid question- when you refer to 1.5% catalyst to mix with the filler- Is that 1.5% of the total volume of all the stuff you mxed together, or is it 1.5% of the poly resin volume? So...if you add 1 qt of cabrosil to 1 qt of resin, then add 1/2 qt of micro ballons...what would be the amount of catalyst you would add to make sure you proper cure? Would it be 1.5 % of 2.5 qts (8 ounces)? or would be 1.5% of the resin (3 ounces)? I am thinking it would be 1.5% of the resin, but cabrosil and micro balloons also make up the mix. Thanks

 

[Woodonglass]

Re: "PB" Components

The "Sticky" exists at the top of the Forum. Here is the link
http://forums.iboats.com/showthread.php?t=286013

As far as mixing the catalyst with the resin, the ratio relates to the resin. You do not consider the thickening agents. Basically Cabosil thickens the resin and the fibers adds strength. Given those facts, it depends on what you are looking for. If you are mixing filler then you would want to use mostly cabosil and probably some microballons and NO fibers. If you are filleting then 40% Cab 60% fibers. It's kinda up to you. But you ALWAYS mix the Resin and Thickening agents first and THEN add the CATALYST LAST, again based on the volume of the Resin used NOT on the total volume of the thickened mixture.

Hope this helps

 

[ondarvr]

Re: "PB" Components

Like others have said already, there is no exact recipe because every resin will be a little different and how you want to use the putty may be different. Cabosil makes a creamy smooth non sagging putty, adding bubbles (they go by many names) will make it lighter and easier to sand, fibers make it stronger, but may make it lumpy and harder to work with depending on how much you add. So just custom mix what works for you at the time.

It is better to add the catalyst prior to mixing in the other stuff, but it's common to mix all the putty you will need for the entire job before you start and then catalyze small amounts as needed.

 

[oops!]

Re: "PB" Components

i add the catalyst first......because its easier to get the resin cat thoroughly mixed.....very difficult to get a good even mixture when the filler is in...

but how you do it is up to you bud...

i would suggest you add the catalyst after you have made your first batch...that way you can "get the feel" of how much stuff you are adding to the resin with out the stress fo the stuff going off on you while you are experimenting.
after you have made your first batch and know what to expect.....than for the second batch, you can add the catalyst first...then the fibers....for a well mixed batch.