Fiberglass Filler / Bondo / Glazing Compound? Can these be used on our motors?

[John Gragg]

What are your experiences/thoughts on using any or all of these body fillers for marine use? I’m already chest-deep in a couple of repairs using some or all of these on various parts of a couple of my projects but I recently saw where a few were discussing absolutely NOT using for marine applications. (Facebook outboard sites)

Did I just waste hours of my time body working, priming and painting a couple of gas tanks etc? (One a TD20, the other a 4 GAL Mile Master)

Hit me hard on this one. I know full well there are products out there “M-A-D-E” for what I am doing. But they are soooooo expensive and I already know how to apply and use these that I have so I thought I would be okay?

What do you all think?

If it’s the wrong stuff, how long will I get out of it with gentle use? (I don’t even own a boat to hang an outboard on, so “test-tank” use only until I can get a small skiff or sell the motor and move on to the next one).

I also don’t want to set up the next owner for a pile of ugliness because of my stupidity.

 

Thanks!

John Gragg
RIverside, CA

Just starting in the hobby, please be patient.

48 Sea King 5hp GG9014A
49 Sea King 5hp GG9014A
48 Johnson TD20
49 Johnson TD20
54 Johnson QD15
55 Johnson CD12

[dillon]

I personally wouldn’t be afraid of using bondo if it sticks good to your project, cars get wet don’t they? and a gas tank isn’t going to be submerged in water anyway. I think there are some types of marine fillers but I have used regular bondo on an outboard before and it was never a problem. If someone tells you not to use it what do they tell you to use?

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John Gragg

[bob-d]

John, I have used it on a bunch of motors without any problems.
On deep dents I use JB Weld as a base, then I put a thinner layer of Bondo on top.
After the Bondo, I use glazing putty on any of the small imperfections.
Bob D

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John Gragg

[John Gragg]

dillon wrote:

I personally wouldn’t be afraid of using bondo if it sticks good to your project, cars get wet don’t they? and a gas tank isn’t going to be submerged in water anyway. I think there are some types of marine fillers but I have used regular bondo on an outboard before and it was never a problem. If someone tells you not to use it what do they tell you to use?

I think it was called USC Allmetal. Supposed to be superior for aluminum filler repair?

Thx for the reassurance.

 

Best Regards

John Gragg
RIverside, CA

Just starting in the hobby, please be patient.

48 Sea King 5hp GG9014A
49 Sea King 5hp GG9014A
48 Johnson TD20
49 Johnson TD20
54 Johnson QD15
55 Johnson CD12

[jeff-register]

John,

If you want to use any filler first try to straighten the metal to avoid thick applications of filler. I have done many boat fiberglass repairs. I would use epoxy sanding resin & powdered fiberglass cloth to mix a putty type mix & apply. Use acetone to clean tools. Another thought with all the new cars with aluminum body panels there must be new products to use now for aluminum apps. Like others have stated epoxy type fillers would work too. Just straighten the metal as much as possable first & keep the filler thin to avoid cracking out.  Be careful with fiberglass resin mixing the hardener, too much & the resin WILL catch on fire. I know from experience & air tempature changes mix ratio. Ive cut boats in half & reglassed for repairs, Look on line fir Filler products possably. Photos of your repairs would help & wear a MASK!! Your lungs were made for O-2 not filler dust please!

1 user thanked author for this post.

John Gragg

[rmhxruss]

Bondo does absorb water. Use Evercoat F27 will not absorb water. Or epoxy.

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John Gragg

[crosbyman]

for small surface  dings  I used JB stuff ..get rock  hard sands like anything else        prep the site and clean it first

 

Joining AOMCI has priviledges 🙂

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John Gragg

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