3M marine premium filler

Is anyone familiar with this product? Does it bond really well to fiberglass boats? Enough so that I could build up a ground down bow and stern keel line with it? Is it the perfect bondo for boats, or will it not take too many hits? Thanks in advance and cheers-----------

Expensive Bondo
From the TDS and other info on the 3M site it looks like just really expensive Bondo.


3M Marine Premium Filler is …

– Last Updated: May-23-11 11:35 PM EST –

...... what I use just about exclusively on fiberglass boats . It's a vinyl ester .

Yes , it's kind of expensive , but I'm hooked on it . If you do chose to get some and use it , do a "few" practice sessions with the mixing of the blue cream hardner and 3M vinyl ester filler base (to get a feel for how quick it moves) ... tip , use less blue cream hardner than you think , 3/4" to a golf ball size is max. and not needed , especially when it's warm out . This stuff will move and set fast so only one small (golf ball size or less) batch at a time . Pay attention to max fill thickness as per directions . You can build it up after cure with consecutive layers if needed .

I have a 16" long by 8" wide piece of sand ply (smooth finish) , that I do the mixing on with a stiff putty knife . Then with variety of 1"-4" putty blades I just take it right off the ply board as needed and apply to fill area .

As soon as my batch starts to get stiffer , I either use it real quick or scrape it off the board into the trash can . Then acetone the blades and ply board surface to clean mostly . Before next batch I use a random orbit on ply surface , and blades as needed , quick acetone wipe and mix again .

The process can not be rushed . At room temp. you can be sanding the newly filled area in 15 mins.

I always acetone (to sterilize) area to be filled , and do the same between build up coats (layers) ... after final fairing to desired shape , put whatever finish you want on the 3M , or just leave it as it is if you don't care . I prefer to gelcoat over it .



Wings, your wasting yer time with the
acetone. It will bond to itself just fine in your quick recoat process.

probably right but …

– Last Updated: May-24-11 5:24 PM EST –

...... often I'll do some sanding inbetween coats .

Partially to begin the fairing and shaping process , partially so the next coat is laid on a smooth surface (easier to build and spread that way) , and partially to tooth it up a bit for the next build up layer .

Usually during those sandings I'll be feathering to the ghost layer at the perimeter of the fill area .

Not sure this 3M stuff but the acetone
wipe ‘could’ make certain fillers curl right up.



Ex. A thick batch of X, cheese gratered/blocked down to near perfect, then a thin coat to super fair / feather edges. Sand to perfection … wipe with acetone and the edges lift …