Refurbishing old solar hot water panels - Page 2

Daox · 11-03-20, 02:24 PM

More progress today. I found a panel that had two leak points in it. I haven't done much sweating of pipe, but I managed to get them sealed up.

How it was.

Cleaned up and ready for flux.

Yay, no more leaks.

I also had this one to fix up. Cleaning it out was a pain. I used a file and sand paper to clean the area. It took a while and two attempts, but its sealed now.

Daox · 11-05-20, 07:34 PM

Today was the last day of pressure testing. Everything has now passed. Hurray!

The next step is to start assembling. Today I got the inserts all put in the cases, and all the inserts got a new thin coat of flat black paint (in the picture is still drying).

Daox · 11-06-20, 02:06 PM

I have a question about the reassembly of these panels. The glass on them has a rough texture on one side of it. I assume this is to refract light and even out the distribution over the panel. My question is, should it be on the outside or inside?

Acuario · 11-12-20, 12:04 AM

Quote:

Originally Posted by Daox

This part is all easy. The hardest part is actually removing the PEX lines. Once they're crimped on there they are very hard to pull off, even after cutting the metal crimps off. If anyone has any tips on how to remove PEX lines from then fittings it sure would be nice.

A very sharp knife and a lot of care! When I have to remove PEX fittings I cut a deep slit into the pipe the length of the fitting following the line of the pipe, but not down to the fitting. At the end of the fitting I cut right into the pipe for about 1cm. Then bending the pipe at the fitting the slit should open up and you can recover your fitting. Be careful not to cut into the fitting as if the ridges are damaged it can leak - particularly the plastic fittings.

Personally I wouldn't use PEX tube for a solar installation. In the past I used a plastic pipe (not PEX) and with the combination of heat and pressure it ended up popping.

Also, if you do use PEX be aware that some (maybe all, I don't know) is very susceptible to UV and degrades and ends up leaking. In Spain the most common is a translucent white PEX and I have seen lots of instances where it has been installed outside by inexperienced people and then has started to leak - I've changed lots to copper. It seems to last about 5 years before failing. It ends up very fragile and almost crystalized, if you try to expand it it just splits so repair is impossible.

solarhotairpanels · 12-22-20, 12:59 PM

My only addition to this thread is beware of stagnation temps using PEX. I would stick with black automotive type radiator hose with stainless clamps or solder copper to join collectors. Just my 2 cents...

Personaly I've been using the automotive radiator hose on my 2 evacuated tube collectors for over 8 years now and no leaks, no issues.

Good luck! looks like a fun project for sure.

11-03-20, 02:24 PM	#11
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	More progress today. I found a panel that had two leak points in it. I haven't done much sweating of pipe, but I managed to get them sealed up. How it was. Cleaned up and ready for flux. Yay, no more leaks. I also had this one to fix up. Cleaning it out was a pain. I used a file and sand paper to clean the area. It took a while and two attempts, but its sealed now. Attached Thumbnails __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

11-05-20, 07:34 PM	#12
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	Today was the last day of pressure testing. Everything has now passed. Hurray! The next step is to start assembling. Today I got the inserts all put in the cases, and all the inserts got a new thin coat of flat black paint (in the picture is still drying). Attached Thumbnails __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

11-06-20, 02:06 PM	#13
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	I have a question about the reassembly of these panels. The glass on them has a rough texture on one side of it. I assume this is to refract light and even out the distribution over the panel. My question is, should it be on the outside or inside? __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

12-22-20, 12:59 PM	#15
solarhotairpanels Helper EcoRenovator Join Date: Mar 2012 Location: Warwick, Rhode Island Posts: 92 Thanks: 22 Thanked 29 Times in 18 Posts	My only addition to this thread is beware of stagnation temps using PEX. I would stick with black automotive type radiator hose with stainless clamps or solder copper to join collectors. Just my 2 cents... Personaly I've been using the automotive radiator hose on my 2 evacuated tube collectors for over 8 years now and no leaks, no issues. Good luck! looks like a fun project for sure. __________________ Pat from Warwick, RI Please Note: Comments and/or suggestions I make here at the forums on 'your' projects as well as my own have all been carefully and scientifically calculated by 'the seat of my pants' To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.