Preliminary Fairing

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Dan_Smullen
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Preliminary Fairing

Post by Dan_Smullen » Thu Dec 05, 2019 5:43 pm

What are the ramifications of some initial fairing at the tape edges prior to laying glass?

Cured tape edges have been sanded. Smooth enough to run a hand over without feeling a splinter, however there is somewhat of a serious "drop off" at the edges of 2 layers of tape and raw plywood. I had some concerns about glass and resin not laying all the way in at these spots.

Just ignore it and build on, or skim with something? Any harm in skimming it with something? High Density Filler? :doh:



Jaysen
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Re: Preliminary Fairing

Post by Jaysen » Thu Dec 05, 2019 5:58 pm

Answered on other three but...

Ignore it. If you fill don’t use fairing compound. Used milled glass silica or wood flour. Sands like hell but you reduce the risk of delam.
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Dan_Smullen
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Re: Preliminary Fairing

Post by Dan_Smullen » Thu Dec 05, 2019 7:08 pm

Hey, Jaysen! Thanks for both responses.

Wood flour, because I have it on hand, is what I planned on using. Going to do it wet on wet so there won't be much to sand.

Jaysen
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Re: Preliminary Fairing

Post by Jaysen » Thu Dec 05, 2019 8:09 pm

Be careful to avoid excessive qty for sure. Exothermic reaction. And the heat from the first layer will speed up the cure of the second. AKA cut your working time.
Visit my official Class Globe 580 build blog at https://jaysenodell.com/globe-580
Currently starting a build of "Lil Bit More". A Class Mini 5.80
Class Mini 580 welcome post.
My already completed 'Lil Bit'. A Martens Goosen V12 set up to sail me to the fishing holes.
Jaysen wrote:
Mon Apr 29, 2019 3:44 pm
I tried to say something but God thought I was wrong and filled my mouth with saltwater. I kept my pie hole shut after that.

fallguy1000
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Re: Preliminary Fairing

Post by fallguy1000 » Thu Dec 05, 2019 9:44 pm

I like to hotcoat those with a 4-6" knife.

But if it is the whole hull bottom; then you can prefill with slow epoxy before your wetout.

If you allow the infill to kick, it will get sticky, but you can prewet over it without the roller picking up the filler.

If you wetout before kick; then you have to be a bit careful to not pull the infill up with the roller AND it will be harder to wetout.

I always infill those tape edges for tapes 17 oz and greater or for any stack greater than 17 oz. I hate air on the hull bottom.

Keep in mind a hotcoat is very sticky, so you will not get any movement of your glass unless you wet out above the hotcoat.

Great question.
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Fuzz
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Re: Preliminary Fairing

Post by Fuzz » Thu Dec 05, 2019 10:35 pm

You can put some wood flour glue along the glass line much like you would do if fairing. While it is still wet go ahead and lay your glass over it. It will not be thick enough to cause you any heat problems.

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Re: Preliminary Fairing

Post by fallguy1000 » Thu Dec 05, 2019 11:59 pm

fallguy1000 wrote:
Thu Dec 05, 2019 9:44 pm
I like to hotcoat those with a 4-6" knife.

But if it is the whole hull bottom; then you can prefill with slow epoxy before your wetout.

If you allow the infill to kick, it will get sticky, but you can prewet over it without the roller picking up the filler.

If you wetout before kick; then you have to be a bit careful to not pull the infill up with the roller AND it will be harder to wetout.

I always infill those tape edges for tapes 17 oz and greater or for any stack greater than 17 oz. I hate air on the hull bottom.

Keep in mind a hotcoat is very sticky, so you will not get any movement of your glass unless you wet out above the hotcoat.

Great question.
Hotcoating has little to do with actual heat. It just means waiting until the coating has exothermed. You will not have a heat issue with a coating under 1/8" if you let it go to gel time and then glass over it.

Just to be clear..
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viewtopic.php?f=12&t=62495

Dan_Smullen
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Re: Preliminary Fairing

Post by Dan_Smullen » Fri Dec 06, 2019 11:51 am

Thanks for the helpful responses, Gents! This is all what I had in mind.

I laid and rolled tape over tacky wood flour/peanut butter and like the way all the layers seem to bond.

I wanted to make sure I wasn’t introducing new unforeseen problems while trying to avoid the gaps that epoxy/cloth may not fill. Sort of bridging over a void below. Can’t have that!

Optimistic this may save me some labor at the fair stage as well. Double bonus!

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Re: Preliminary Fairing

Post by Jeff » Fri Dec 06, 2019 12:21 pm

Good results Dan!!!! Jeff

fallguy1000
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Re: Preliminary Fairing

Post by fallguy1000 » Fri Dec 06, 2019 2:37 pm

Won't save any fairing; sorry.
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