Faring dos and donts questions

[LakeFever]

Is faring over structural glass acceptable practice or is it required to lay csm over all structural glass prior to faring?

cracks in existing hull can these be left and sandwiched between layers of structural glass or do they need to be ground completely out and filled with csm first?

[rgsauger]

Hell. I figured you would’ve had 15 good responses by now. I’m wondering the same thing

[LakeFever]

Mid winter, not so much action on boat stuff I guess. To avoid risking shrink and print problems later on I decided to lay 1oz csm over everything I’m going to fare first. More time and money but I don’t have any prior builds to gauge this by being my first fiberglass resto and all.

[VkingMike]

Also curious on fairing for a smoother finish. This 1708 is quite a rough surface once cured

[LakeFever]

If your going to lay csm over the 1708 it takes less than half the resin if you lay it wet on wet. In my case laying 1708 on the exterior skin and 1oz csm over top I’m also tailing the 1708 by running the csm an inch or two past the edge of the 1708 to tie it in and smooth the transition. This will be followed with one coat of waxed gel to cure it and it will be cut with a da using 40 grit until smooth. Faring putty over this all with a huge spreader done in thin coats. I estimate 3-4 coats of faring putty to smooth it in this manner. We will be using dura block sanding block with 80 grit to cut the putty. I have an assortment of these blocks the longest one is 30” long called the marine block. After the faring looks smooth we will be using guide coat to reveal any lows. Sharpening will be done to all strakes and edges and then finally sprayed with gel and possibly duratec ve primer prior.

This is what I know and how I am planning to do it. Was hoping for some tips and tricks from the seasoned pros that might help. I wanted to fare directly over the 1708 but won’t risk it without affirmation that this holds up well over time. Hope this helps some of you out


edit: I also did grind out all the cracks and whiteish damaged looking areas and filled with csm, gel coated with wax, cut and blended in with 40 grit on the da. Some of the deeper areas took about 5-7 layers of 1.5oz csm to fill proud side there was enough meat to blend it down smooth. Worked slick there’s pics in my build thread if you would like to see the process

[tnelsmn]

Wish I knew an answer for ya.

[LakeFever]

Lol thanks Tnels. We have a sound plan it’s just the long road no short cuts or tricks involved. Maybe there are no tricks here perhaps it was all merely a pipe dream. There is some good that comes from these threads and delays though, it forces me to think about the process longer than I typically would and I can visualize more of what we are about to do before we do it which boosts quality and eases workflow quite a bit.

[powerabout]

are these internal or external cracks
dont quite undertand what kind of repair it is?

[XstreamVking]

When it comes to cracks, glass over the damaged glass is the only way to stop them from coming back. Filler should not be more than 1/8'' thick max. (it won't flex and will crack) Fill low areas with chop before fairing.

[LakeFever]

The cracks are all gone I completely sanded them out. They were in the gel and in the outer skin of the hull. I was always planning to cover them with new glass but feeling the time pressures that are starting to mount with this project we were trying to save time and leave the cracks and skin over them thinking that the new glass plus the solid backing would be ok and the cracks would not print through over time.

we have since moved well past this and committed to grinding out all cracks and filled them with csm and fared them In which worked out very well.

as for the putty xstream I’m with you 100% on that we are trying to fare the hull with pure glass leaving the putty for skim only. Thankfully having body work experience this process is at least familiar. Now that we have repaired all the cracked areas with csm we both agree the hull could be gel’d and wrapped up and be fine as is. We have already committed to skinning with 1708 with csm on top and faring that out before gel.

appreciate the replies and info guys

[MattGreen]

The glass/rigging shop I used to work at would fair solid glass (matt) for all structural repairs. I was lucky enough to never do that personally (I did mostly more finnicky jobs). We had this old Russian guy who was the definition of "old man strength" who could push a big fairing board all day. Putty was only used for filling little pinholes and nicks. Listen to Xstream like usual. In my experience on my own projects good sandpaper is worth the money.

Matt

[LakeFever]

I’m with that 100%

my whole approach being a pleasure user not a racer is to put strength and durability over peak performance. I have posted pics of most of this in my build thread but if you want a visual of what I was concerned about in my initial post here’s a few and one before after so you can see how it is now. All the cracks are gone. We are planning to use kitty hair to rough fare the pad before we lay the new glass over. We are going to sharpen the lines with kitty hair and csm for maximum strength

[bakerfreak]

Any suggestions for fairing over 1708 with epoxy resin? I've read that you shouldn't use CSM with epoxy. Should I just use fairing putty directly on the epoxy?

[XstreamVking]

Sand it to rough it up. Wipe with alcohol and use epoxy fairing compound. Awl fair is a good one. Epoxy primer and a good top coat of your choice

[LakeFever]

I spoke with many people about this and heard as many opinions on the approach. At the end of the day shrink and print through are the concerns and until i have twenty years of time to see how the faring putty and gel i used shrink? Its still a guess to me. That said id fare over 1708 without worry if i was going at this again. Sanding all that csm down took a lot of time