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3M High Strength Repair Filler
$113.81In Stock
3M High Strength Repair Filler
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3M High Strength Repair Filler Customer Questions and Answers

9 of 9 Questions

Question

Can gelcoat be applied over this product?

Asked on 01/28/2012 by Undisclosed

Top Answer

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!

Answered on 01/30/2012 by ANTHONY HUDEK
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Answer

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).

Answered on 01/30/2012 by IAN UPDIKE

Answer

Yes as far as I know it will work. I used epoxy over top of it without any problems.

Answered on 01/31/2012 by DOUG DILLMAN

Answer

Yes, this is a quality product that works very well with gelcoat. Minimal shrinkage and all around a good choice with gel.

Answered on 01/31/2012 by RANDY WESLOW

Answer

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.

Answered on 01/30/2012 by MARK REYNOLDS
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Question

can I use this on aluminum as a faring compound also ?

Asked on 01/30/2013 by Undisclosed

Top Answer

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.

Answered on 01/30/2013 by MARK REYNOLDS
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Answer

This product is not designed for faring, it is far too strong and would be very difficult to sand.

Answered on 01/30/2013 by ROBERT WEDGE

Answer

No idea.

Answered on 02/06/2013 by ROBERT NEUMANN

Answer

I have only used this product on fiberglass and it is very strong.

Answered on 01/30/2013 by ROBERT MCLEISH
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Question

Can I use this to repair dings in my keel due to grounding? What should I prep the Lead with?

Asked on 02/19/2013 by Matt Wallis

Top Answer

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.

Answered on 03/04/2013 by ROBERT MCLEISH
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Answer

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..

Answered on 03/01/2013 by MARK REYNOLDS

Answer

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 .

Answered on 03/01/2013 by ILARIO FAZZARI
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Question

will this work on wood?

Asked on 04/13/2012 by Undisclosed

Top Answer

Yes. Most of my use has been on wood. I don't think you can use it over epoxy, however.

Answered on 04/13/2012 by ROBERT NEUMANN
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Answer

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.

Answered on 04/19/2012 by ROBERT WEDGE

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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

Answered on 04/13/2012 by MARK REYNOLDS
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Question

do you think this would adhere to small soft patches of verticle masonite siding?

Asked on 10/12/2011 by Undisclosed

Top Answer

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.

Answered on 10/12/2011 by KEVIN DAVIS
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Answer

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.

Answered on 10/13/2011 by BILL SMALLWOOD

Answer

YES, I'm sure it will, but it my be a little over kill.

Answered on 10/12/2011 by GARY WALKER
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Question

can this be used on wood?

Asked on 09/15/2014 by tom perhay

Top Answer

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.

Answered on 09/16/2014 by DAVID BIRD
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Answer

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.

Answered on 09/15/2014 by Jack of All Jack of All
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Question

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

Asked on 10/02/2012 by Undisclosed

Top Answer

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.

Answered on 10/02/2012 by KEVIN DAVIS
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Answer

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.

Answered on 10/02/2012 by MARK REYNOLDS
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Question

Is PVA or other air-inhibited overcoat required for full surface cure of HSRF?

Asked on 07/19/2021 by Steven from NJ

Top Answer

No, simply add the hardener and these products will be ready to sand within 30 minutes of application.

Answered on 08/13/2021 by Paul
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Question

Will this work on scrapes in the hull under the water line?

Asked on 06/18/2012 by michael burke

Top Answer

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.

Answered on 06/20/2012 by ROBERT WEDGE
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