Author Topic: Sand thruís / burn thruís, what can I get away with?  (Read 1005 times)

surfcowboy

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Sand thruís / burn thruís, what can I get away with?
« on: May 07, 2020, 08:54:11 PM »
Asking for a friend. lol

Iím finishing this foil SUP and trying to just prototype and not be a perfectionist. Iím shooting for say somewhere between Pono and Big Green. (Sorry guys, I had to, yíall made it ok for me to just go for it and Iíll never repay the fun Iíve had.)

But as far as watertight, do burn through spots leak? Iím figuring thereís some sort of capillary action around them but I wanted to ask.

Iíll probably just spot fix instead of another hot coat to keep weight down but Iíve never seen this discussed. Iíve gotten way faster at sanding but even with it, Iím trying to move fast and get these into the water and figure out the next size or shape without a lot of fuss.

eDUBs

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Re: Sand thruís / burn thruís, what can I get away with?
« Reply #1 on: May 07, 2020, 10:51:58 PM »
Spot fix and be done

surfcowboy

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Re: Sand thruís / burn thruís, what can I get away with?
« Reply #2 on: May 07, 2020, 11:00:28 PM »
The master has spoken!  Thx man.

Iím still curious about water tightness but you are not the cat for that. I doubt youíve ever done an ugly repair in your life. ;)

Dwight (DW)

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Re: Sand thruís / burn thruís, what can I get away with?
« Reply #3 on: May 08, 2020, 03:05:01 AM »
Ultrasonic leak testing every board before it goes out the door is the only way to be 100% sure.

jrandy

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Re: Sand thruís / burn thruís, what can I get away with?
« Reply #4 on: May 08, 2020, 06:39:54 AM »
SC, I have a 'friend' that sands through rails too.  He's half done with a board for his daughter...

DW, Is ultrasonic leak testing something that people with liberal arts degrees can do or ? Gizmo + procedure?
http://pushheretosavealife.com/
Be safe, have fun. -J

Dwight (DW)

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Re: Sand thruís / burn thruís, what can I get away with?
« Reply #5 on: May 08, 2020, 07:04:50 AM »
Attach a vacuum pump to the goretex port. Scan the board using a ultrasonic leak detector. Easy, but expensive test device.


TallDude

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Re: Sand thruís / burn thruís, what can I get away with?
« Reply #7 on: May 08, 2020, 01:35:31 PM »
There are a lot of different types of "ultrasonic" testers that are used for different applications. There are the kind that are used for non-destructive testing of metals which use different types of sensors / transducers that give feed back to an oscilloscope. It's still using sound, but it's measured differently. The type you are looking for is one that has a small microphone / transducer that can hear in the non-audible range of ultrasonic. The devices vary in sensitivity. Some hear better than others. Since we can't hear that high of a frequency and amplifying it still won't help us hear it, we need it converted to a lower (audible) frequency. The cheap devices use a pitch shift circuit to do that but, the microphone / transducer is crap, and you have to use your Punk Rock spent ears. You pay more money for a better microphone (more sensitive), better circuitry, and a some sort of electronic meter that registers when a leak is detected. No headphones needed. These cost a lot more.
Some come with ultrasonic sound generators that create the sound on one side (of say a wall), and the receiver/ detector on the other side. With a board, the vacuum pump is drawing air into the board, and where ever there is a pinhole leak it will hiss in the ultrasonic sound spectrum. I would imagine the smaller the leak, the higher the frequency, the more sensitive the listening needs to be. 

$30 crap
https://www.youtube.com/watch?v=9WZ33q_JKjo

https://www.youtube.com/watch?v=PO2qFPSqDbA

https://www.youtube.com/watch?v=sR7uadt_0CY


Maybe better?
https://www.amazon.com/allsun-Ultrasonic-Transmitter-Headphone-Indication/dp/B079DPF98V?ref_=s9_apbd_orecs_hd_bw_b5RefH1&pf_rd_r=AD44QR4KWHZQB696E1R6&pf_rd_p=632b5992-e713-5dcb-a62f-a4fc1306dfcd&pf_rd_s=merchandised-search-10&pf_rd_t=BROWSE&pf_rd_i=4989317011

Good.
https://www.amazon.com/dp/B07XMNYJF2/ref=sspa_dk_detail_0?pd_rd_i=B07XMNYJF2&pd_rd_w=idIqp&pf_rd_p=48d372c1-f7e1-4b8b-9d02-4bd86f5158c5&pd_rd_wg=sgB0D&pf_rd_r=EHJA2CETPE8ZWQ5G5C3Z&pd_rd_r=45571fca-acb5-4ff6-a303-37b23a612ab8&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUExSEJXUUZZV1U1TVBCJmVuY3J5cHRlZElkPUEwNDQwNzMyMkxVRkE3WVNSWlRMOCZlbmNyeXB0ZWRBZElkPUEwNjA4Mjk3M0RCQ1VHMVlWWUExSyZ3aWRnZXROYW1lPXNwX2RldGFpbCZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU&th=1


It's not overhead to me!
8'8" L-41 ST and a whole pile of boards I don't use.

surfcowboy

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Re: Sand thruís / burn thruís, what can I get away with?
« Reply #8 on: May 08, 2020, 08:44:52 PM »
DW I was looking at the cheaper ultrasonic testers on eBay. TD thx for the reviews.

Iím for sure weighing this one before it hits the water. Now to go watch those reviews. But Iím figuring they are better that a stethoscope lol.

surfcowboy

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Re: Sand thruís / burn thruís, what can I get away with?
« Reply #9 on: May 08, 2020, 08:45:50 PM »
Oh, and it looks better today. Something to be said for patience and a fresh perspective.

surfcowboy

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Re: Sand thruís / burn thruís, what can I get away with?
« Reply #10 on: May 10, 2020, 06:57:42 PM »
Ok I forgot how things you can add resin when. You're not fill coating. I haven't had to do it in a while and it was so easy that I painted a couple of.low spots too.

Also went for it on the rails.

Here's a pic so no one else feels ashamed of a little aggressive sanding.


TallDude

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Re: Sand thruís / burn thruís, what can I get away with?
« Reply #11 on: May 10, 2020, 07:44:21 PM »
You have to sand boards a lot to get really good at it. I don't, so I'm not.  ::)
It's not overhead to me!
8'8" L-41 ST and a whole pile of boards I don't use.

jrandy

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Re: Sand thruís / burn thruís, what can I get away with?
« Reply #12 on: June 05, 2020, 07:52:23 PM »
You have to sand boards a lot to get really good at it. I don't, so I'm not.  ::)

TD, Word.

SC, if you want something to chuckle about, I have that one board from about 2 years ago that I did so poorly on the rails...well long story short after 19 months of wallowing in shame and a 'fresh perspective' as my daughter decides it's hot outside and it needs to get done. We just came in from patching about 20 different skippers and sand-throughs. Awesome to have her help and her playlist and someone to motivate me to complete it. Maybe I'll bump the thread...
http://pushheretosavealife.com/
Be safe, have fun. -J

surfcowboy

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Re: Sand thruís / burn thruís, what can I get away with?
« Reply #13 on: June 05, 2020, 09:38:41 PM »
Amazing. In the end itís mostly smoothed lol. But Iíve decided not to worry about a foil SUP. So many knocks and scratches that itíll be constantly filled and such, so Iím running it pretty raw. Looks great in the water lol.

Iíll try a little harder on my prone foil as I suspect itíll see less knocking around.

 


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