Seacraft trailer rash

Questions about boat repairs with our resins and fiberglass: hull patches, transoms and stringers, foam, rot etc.
Seacraft86
New Poster
New Poster
Posts: 4
Joined: Fri Apr 02, 2021 4:20 pm
Location: S Florida

Seacraft trailer rash

Post by Seacraft86 »

First post here. Been ready through a few build threads (the 21 michael fitz In particular). Definitely lots of good ideas on here.

My question is how deep do I need to sand into my fiberglass before I start laying new glass in? The area I’m repairing is the forward part of the keel that gets beat up beaching and trailering. It had a few nasty gouges that I’ve sanded down to what I think is clean enough glass to start building it back up.

Here’s a few pictures. Should I keep grinding?Any advice would be greatly appreciated.

[
848354BA-B57C-42CC-BB6A-C3004F85CA08.jpeg
36B81C1B-F81F-443A-8175-8DDF9C768B3D.jpeg
56568EF4-59D1-4AB3-9C27-C4A9DE431C8A.jpeg
23073F85-A247-4656-8E23-AA992CB9DEEF.jpeg

fallguy1000
* Bateau Builder - Expert *
* Bateau Builder - Expert *
Posts: 10198
Joined: Tue Jan 12, 2010 12:25 am

Re: Seacraft trailer rash

Post by fallguy1000 »

You can't leave any loose or broken glass unless you can access and add to the other side.

I would get some milled fiber and cabosil about 50/50 by volume with epoxy pretty thick and force it into the deep grooves.

Building up a groove like this is done smallest to largest. It is best done with chopped stand mat and epoxy. Do not cut the edges, but tear them.

Smallest piece in the deepest groove until you have enough thickness to allow for gel or paint.

Sand with 80 grit, get rid of the frayed edges of mat.

Finish as needed with primer n paint or gel.
My boat build is here -------->

viewtopic.php?f=12&t=62495

Seacraft86
New Poster
New Poster
Posts: 4
Joined: Fri Apr 02, 2021 4:20 pm
Location: S Florida

Re: Seacraft trailer rash

Post by Seacraft86 »

There isn’t any loose glass left and I grinded out all of the cracks and gouges. Are all the white areas broken glass? The surface is sanded with 80 grit. CSM is better suited that 1208 or 1708? Since this is a overhead lamination my plan was to coat the area in unthickened epoxy and wait for it to get tacky before laying glass.

Thank for the replys

fallguy1000
* Bateau Builder - Expert *
* Bateau Builder - Expert *
Posts: 10198
Joined: Tue Jan 12, 2010 12:25 am

Re: Seacraft trailer rash

Post by fallguy1000 »

You can use the 08 series, but csm only is really nice for repairs such as these because it is tearable and finishes so well

Some people take plastic and a sharpie and trace out the shapes and decide based on the thicknesses how many pieces to make.

I only suggested the filler mix because it looks kinda lumpy, but that could be the picture. If it is smooth and not super rough, then you can hotcoat it like you said...

Also, if you want to use 08 glass, leave the csm side up if you plan to gelcoat.

The 08 glass is used on bigger areas and 1708 is about 0.050" thick, while 1208 is about 0.035, so usually these fabrics are too thick to fix a repair that ranges from say 0.060 to feather thin on the edges.

I will link a video. Give me a second.
My boat build is here -------->

viewtopic.php?f=12&t=62495

fallguy1000
* Bateau Builder - Expert *
* Bateau Builder - Expert *
Posts: 10198
Joined: Tue Jan 12, 2010 12:25 am

Re: Seacraft trailer rash

Post by fallguy1000 »

If you want to gelcoat, use polyester.

If you plan to paint, use epoxy. Epoxy is a very strong glue and doesn't need to break down csm binders to work, so don't get all wrapped up in that bs.

Deleted the link to the wrong video.
Last edited by fallguy1000 on Sat Apr 03, 2021 9:04 am, edited 1 time in total.
My boat build is here -------->

viewtopic.php?f=12&t=62495

fallguy1000
* Bateau Builder - Expert *
* Bateau Builder - Expert *
Posts: 10198
Joined: Tue Jan 12, 2010 12:25 am

Re: Seacraft trailer rash

Post by fallguy1000 »

Oops!

Here is the one you need for less than a hole. He goes into good details on the resins as well.

But here he explains how to feather the edges of thin csm for shallow repairs like yours.

https://youtu.be/Zka0i0SOGd8
My boat build is here -------->

viewtopic.php?f=12&t=62495

Seacraft86
New Poster
New Poster
Posts: 4
Joined: Fri Apr 02, 2021 4:20 pm
Location: S Florida

Re: Seacraft trailer rash

Post by Seacraft86 »

Thanks for the advice. I’ve watched a lot of boatworks today and have learned a lot. My plan as of now is to sand a little deeper to try and get through those white sections of glass that look like they could possibly be damaged. Then I’ll brush on some epoxy and wait until in tacks up. I’m thinking 1208 and epoxy will give me the strongest repair. Worried the 1708 soaked in resin will be too heavy to stick upside down but not really sure... going to lay the 1208 small to large wet on wet and finish it with a milled fiber and microbaloon fairing putty before it all kicks. I have some leftover interlux interprotect 2000 that I’ll go over the repair after it cures. I called interlux support yesterday to see if I could paint it on tacky epoxy and got a hard no so I’ll have to scotch right and sand before painting.

Sound good?

I like the idea of csm being easier to work with and fair but I really want this repair to be as strong as possible. I’ve seen boats crack from the forefoot being worn thin.

Seacraft86
New Poster
New Poster
Posts: 4
Joined: Fri Apr 02, 2021 4:20 pm
Location: S Florida

Re: Seacraft trailer rash

Post by Seacraft86 »

Just a few pictures of the boat because who doesn’t like boat pics!

C2000F8C-C899-4AB2-859B-86749121C71D.jpeg
5618C082-E97E-4BA3-8CDB-1ED333A1AF43.jpeg

fallguy1000
* Bateau Builder - Expert *
* Bateau Builder - Expert *
Posts: 10198
Joined: Tue Jan 12, 2010 12:25 am

Re: Seacraft trailer rash

Post by fallguy1000 »

Seacraft86 wrote: Sat Apr 03, 2021 10:11 am Thanks for the advice. I’ve watched a lot of boatworks today and have learned a lot. My plan as of now is to sand a little deeper to try and get through those white sections of glass that look like they could possibly be damaged. Then I’ll brush on some epoxy and wait until in tacks up. I’m thinking 1208 and epoxy will give me the strongest repair. Worried the 1708 soaked in resin will be too heavy to stick upside down but not really sure... going to lay the 1208 small to large wet on wet and finish it with a milled fiber and microbaloon fairing putty before it all kicks. I have some leftover interlux interprotect 2000 that I’ll go over the repair after it cures. I called interlux support yesterday to see if I could paint it on tacky epoxy and got a hard no so I’ll have to scotch right and sand before painting.

Sound good?

I like the idea of csm being easier to work with and fair but I really want this repair to be as strong as possible. I’ve seen boats crack from the forefoot being worn thin.
It all depends on the depth of the repair. If you have, like I said, 0.080 thickness; you can only get one 1708 in there in the deep spot and then you need to build more glass to the edges with thinner glass. Unless you don't care if you make a hump?

The 1708 will stick upside down just fine for that little area. I have done my share of upside down and csm or 1708 works well with all the fiber directions. But so thick; it is really wrong here. The 1208 is thinner, but two layers is about 0.070" and it might also benefit with some light csm. You can get it at auto parts store. Might be heavier.

You don't add milled fiber to fairing mix; it will be all draggy and clump on you.

Since you are painting, you do want to sand, and you don't want outgassing, so full cure.
My boat build is here -------->

viewtopic.php?f=12&t=62495

Post Reply

Who is online

Users browsing this forum: No registered users and 7 guests