3M Marine High Strength Repair Filler is for bonding and filling repairs above or below the waterline. 3M filler allows you to achieve professional repair results. These pre-mixed products utilize a benzyl peroxide creme hardener and do not require multiple mixing steps, extenders, fillers or pumps.
Simply add the hardener and these products will be ready to sand within 30 minutes of application. Strength is achieved by a unique vinyl ester formulation designed with short strand fiberglass for semi-structural repairs, above and below the waterline.
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Excellent bond strength
Blue Creme hardener
Number Of Parts:
Rate Of Cure:
can this be used on wood?
Yes it can. Keep in mind that the material is very hard and durable so I would suggest that this be used carefully as a base coat especially on wood. Keep the first coat tight or even a tad low to the surface of the wood. Then fair it out with a more appropriate filler.
As long as the wood is dry and lightly roughed up. Another point is spread only what is needed as this product sands quite hard.
Jack of All Jack of All
Can I use this to repair dings in my keel due to grounding?What should I prep the Lead with?
Yes, you can use it to repairs dings in the keel. I had a small horizontal crack in the bottom of my keel that I filled and it has stayed tight after two seasons.
Yes this will work fine. It is a lot of volume - must be a big ding. This is material will harden much harder than lead in the keel so it may be difficult to fair out. I. If I had this I would use it, but if I had West Epoxy with some filler I would probably prefer that since epoxy generally adheres to surfaces better than polyester..
You should repair lead with lead. If the dings are small enough you can use a file to clean them up. I would use the high strength filler to repair fiberglass .
can I use this on aluminum as a faring compound also ?
Normally HSRF is too hard for use as a fairing compound because it is so hard and hard to sand - as soon as you get to the substrate it the substrate sands off more quickly than the HSRF and your surface will not be fair. Relative to aluminum it might be better so for instance to repair a ding in an outboard lower unit if might be a good choice.
This product is not designed for faring, it is far too strong and would be very difficult to sand.
I have only used this product on fiberglass and it is very strong.
I have some stripped screw holes to fill, re-drill, and fasten back down. What filler should I be using in my fiberglass/gel coated boat, and do I have to tap the filler or can I just screw in? BTW, screw holes won't be visible so no need to worry too much about cosmetics. Thanks in advance!Dom
It kind of depends on how thick the material is. You could probably use the hsrf to do that. Can you access both sides of the repair, so that you could have a bit of build up on the back side to give more "bite" for the screws? Depending on how that all looks, one option would be to just fill the holes with epoxy, let it cure, drill a small pilot hole, and screw it in, instead. That might be easier to work with.
3M HSRF is very hard and I would recommend tapping it if you are using a machine screw (unlikely). If you are using a wood screw since there is no tap you may want to experiment with the hole diameter in a sample first . The best diameter may be larger wth a deep hole than a shallow hole.
Will this work on scrapes in the hull under the water line?
Yes, but if the scrapes are cosmetic, use Interlux Watertight instead. It is easier to sand and fair. The 3M product is excellent if you need some structural support. It is very strong thereby hard to sand and is not intended for fairing.
will this work on wood?
Yes. Most of my use has been on wood. I don't think you can use it over epoxy, however.
I have no experience with this product on wood, best to look up the specs from 3m. This product cures extremely hard which is why they do not recommend it for any fairing applications.
Yes, as long as the wood is dry. The HSRF is much harder than wood so fill to just below the final surface and then do final surface with bondo or perhaps a west epoxy with filler (something sandable) then paint
Can gelcoat be applied over this product?
I don't know if this will answer your question, but I used this for reinforcing the joints in a fiberglass Kit Car Body, that had a gelcoat final covering. I had to grind out the seams till the gelcoat strip was absent, then mixed up and applied the 3M HSRF. From research, I found out that the HSRF will adhere to the fiberglass and make a stronger bond between each body panel. A recomenation, I taped each side of the ground out seam, this was to eliminate as much excess as possible. Very good stuff, very strong, and very hard when cured! After knocking the roughness down with 80 grit on my DA sander, I covered it up with Rage putty. I've used this in repairing broken pieces in plastic, still holding strong. I hope I was able to help!
3M High Strength filler has vinyl-ester resins, so, you can apply gelcoat to it. Vinyl-ester gelcoat is available and works very well (I only know of one company that sells VE gelcoat thru mailorder - epoxy paint has largely taken over). I only use VE gelcoat because it's tough/affordable/great adhesion. I've never used regular old gelcoat over 3M filler. I'd encourage you to test first because I don't know the exposure of the repair (topside/bottom/interior).
Yes as far as I know it will work. I used epoxy over top of it without any problems.
Yes, this is a quality product that works very well with gelcoat. Minimal shrinkage and all around a good choice with gel.
Yes you can apply gelcoat over the HSRF. This is a fast hardening (relatively) polyester product. It is also very hard/hard to sand. 3M recommends building up to below the final surface and then doing the final surfacing with something that is easier to sand (?such as lightweight auto body filler?). Just last night I gave a quick wipedown to a part that had some HSRF in it with a paper towel dampened with acetone, not really wet at all, and I was surprised how quickly and how much the HSRF softened - so I won't do that again.
do you think this would adhere to small soft patches of verticle masonite siding?
For that sort of thing, you can use old fashioned bondo, assuming you can seal and paint the area to prevent water. I'd say that would be easier to use and blend in. I just used bondo to repair the under side of my countertop in the kitchen and it worked great.I do think, however, that the HSRF will do what you want, but you have to have a decent surface to adhere to so keep that in mind.
Yes I think it would. In my experience it sticks to resin sanded smooth on a verticle surface so masonite shouldn't be a problem. Just go over it a little with coarse sandpaper before applying.
YES, I'm sure it will, but it my be a little over kill.
Good stuff, need air sander
High Strength = Hard as Nails
Used to fill in holes on painted deck. Very easy to apply, and stays workable for a long time. Once hardened it is extremely durable, even a belt sander had trouble with it. After application, weather rained for 3 days, but it stayed well bonded until we could paint it. Highly recommended high strength filler.
San Diego, CA
It comes with the blue creme hardener
I bought this product to do some hole patching and repair on my Boston Whaler. For this purpose, it met expectations quite nicely. The product does come with a tube of the hardener under the lid (I wasn't sure about this when ordering online, so I bought an unnecessary extra tube). I found the product easy to work with and bonded very nicely to the hull. The resulting color is a pale greenish-blue, if that matters to you.
After several personal test , product prove to be extremely strong in its ability to bond parts to each other .