RV-7A JCarne - Page 40

jcarne · #**391** 07-11-2019, 08:38 AM

Quote:

Originally Posted by kentlik

What type if resin and such are you using? I am interested in getting it in the shop for later.

I use West System epoxy. Get it from here. Looks like there is a couple of stores in the Portland area too. I got mine from Merrit supply when I ordered Sika only to find out the next day that West Marine has free shipping.

You want the 105 resin and the 206 hardner (I bought the gal. size for 105 and 27 oz. for 206) The 206 resin has to be used in temps above 60. I also have the pumps that you can get but I don't really use them other than to dispense as they are not accurate. I weigh everything in a 5 to 1 ratio.

kentlik · #**392** 07-11-2019, 08:53 AM

Quote:

Originally Posted by jcarne

I use West System epoxy. Get it from here. Looks like there is a couple of stores in the Portland area too. I got mine from Merrit supply when I ordered Sika only to find out the next day that West Marine has free shipping.

You want the 105 resin and the 206 hardner (I bought the gal. size for 105 and 27 oz. for 206) The 206 resin has to be used in temps above 60. I also have the pumps that you can get but I don't really use them other than to dispense as they are not accurate. I weigh everything in a 5 to 1 ratio.

Copy that. Thanks for the info! I need to get some flox I guess which is from Spruce I would imagine...

jcarne · #**393** 07-11-2019, 08:58 AM

Quote:

Originally Posted by kentlik

Copy that. Thanks for the info! I need to get some flox I guess which is from Spruce I would imagine...

Ya you probably want to lock down some flox, micro, and cab-o-sil from spruce. Probably get some peel ply too. Flox is strustural to some degree, micro is mainly used on cosmetic things and is easy to sand. Cab-o-sil basically makes it so it doesn't flow/fall when on vertical surfaces.

kentlik · #**394** 07-11-2019, 02:44 PM

So I got all that ordered and on its way. Started back with the fuel lines and bulkhead fittings and going along again but still ready to be done with this part...Return lines are a bit of challenge.

wjb · #**395** 07-11-2019, 04:06 PM

Quote:

Originally Posted by jcarne

You want the 105 resin and the 206 hardner (I bought the gal. size for 105 and 27 oz. for 206) The 206 resin has to be used in temps above 60. I also have the pumps that you can get but I don't really use them other than to dispense as they are not accurate. I weigh everything in a 5 to 1 ratio.

The 5:1 ratio is by volume; by weight it's 5.36:1 for the 206 slow hardener and 5:19:1 for the 205 Fast hardener ... though the data sheet calls out a large range around these for an acceptable mix (5:1 is in the middle of the range). I use a 0.1g scale to measure mine as well; the pumps are not particularly accurate. I never had a batch not cure rock hard doing it this way.

bobnoffs · #**396** 07-11-2019, 04:30 PM

7 ounces of hardener is $22 shipped on ebay.

kentlik · #**397** 07-11-2019, 06:20 PM

Quote:

Originally Posted by bobnoffs

7 ounces of hardener is $22 shipped on eBay.

Back many years ago I was a model maker for industrial design and I still have my vacuum pump and scales...glad I kept them.
Not much experience with glass I will admit. Do I need to roll out the extra resin between a plastic sheet before applying the glass? I saw someone on here doing that. I will have to brush up on this stuff before I get in to it...

wjb · #**398** 07-11-2019, 08:30 PM

Quote:

Originally Posted by kentlik

Back many years ago I was a model maker for industrial design and I still have my vacuum pump and scales...glad I kept them.
Not much experience with glass I will admit. Do I need to roll out the extra resin between a plastic sheet before applying the glass? I saw someone on here doing that. I will have to brush up on this stuff before I get in to it...

If you were building a Lancair or VariEze -- an all-glass plane -- yes, you should be concerned with the proper ratio of glass to resin. However, there are not very many glass components on an RV, and none are structural (maybe the cowl, but that comes from Vans pre-molded from a pro shop), so a little extra resin won't hurt much in weight or strength. It is good practice to wet out the glass and squeeze off any grossly extra resin; that's just wasted weight. You can pre-wet the glass on plastic before applying, or paint the resin on and stipple it into the weave, depending on the application.

Best tip: read every post by DanH on this forum; you'll learn a ton! (and might get a free plenum out of the deal ;-)

And, experiment! It's easy to do, relatively cheap and fast. After reading and experimenting, I was able to totally crush the mis-fit of my IO-360 snorkel. See http://www.vansairforce.com/communit...4&postcount=54. It was very educational and recreational (and fun!)

kentlik · #**399** 07-12-2019, 06:45 AM

Quote:

Originally Posted by wjb

If you were building a Lancair or VariEze -- an all-glass plane -- yes, you should be concerned with the proper ratio of glass to resin. However, there are not very many glass components on an RV, and none are structural (maybe the cowl, but that comes from Vans pre-molded from a pro shop), so a little extra resin won't hurt much in weight or strength. It is good practice to wet out the glass and squeeze off any grossly extra resin; that's just wasted weight. You can pre-wet the glass on plastic before applying, or paint the resin on and stipple it into the weave, depending on the application.

Best tip: read every post by DanH on this forum; you'll learn a ton! (and might get a free plenum out of the deal ;-)

And, experiment! It's easy to do, relatively cheap and fast. After reading and experimenting, I was able to totally crush the mis-fit of my IO-360 snorkel. See http://www.vansairforce.com/communit...4&postcount=54. It was very educational and recreational (and fun!)

Thanks, Bill! I have read closely Dan's stuff on many aspects of construction and it has helped me get up the curve with less pain and suffering...lol

jcarne · #**400** 07-12-2019, 09:01 AM

Quote:

Originally Posted by kentlik

So I got all that ordered and on its way. Started back with the fuel lines and bulkhead fittings and going along again but still ready to be done with this part...Return lines are a bit of challenge.

Heck ya, keep the train rollin!

Quote:

Originally Posted by wjb

The 5:1 ratio is by volume; by weight it's 5.36:1 for the 206 slow hardener and 5:19:1 for the 205 Fast hardener ... though the data sheet calls out a large range around these for an acceptable mix (5:1 is in the middle of the range). I use a 0.1g scale to measure mine as well; the pumps are not particularly accurate. I never had a batch not cure rock hard doing it this way.

Interesting where did you find this ratio by weight? West System website says 5 to 1 for weight or volume. Whoops, never mind, I see it in the TDS. Ya you right though, there is a really large range which makes sense to me because before I started doing any fiberglass work I did a few samples that were purposely mixed wrong and put in about 45 degree weather and I never had anything not cure.

Quote:

Originally Posted by wjb

If you were building a Lancair or VariEze -- an all-glass plane -- yes, you should be concerned with the proper ratio of glass to resin. However, there are not very many glass components on an RV, and none are structural (maybe the cowl, but that comes from Vans pre-molded from a pro shop), so a little extra resin won't hurt much in weight or strength. It is good practice to wet out the glass and squeeze off any grossly extra resin; that's just wasted weight. You can pre-wet the glass on plastic before applying, or paint the resin on and stipple it into the weave, depending on the application.

Best tip: read every post by DanH on this forum; you'll learn a ton! (and might get a free plenum out of the deal ;-)

And, experiment! It's easy to do, relatively cheap and fast. After reading and experimenting, I was able to totally crush the mis-fit of my IO-360 snorkel. See http://www.vansairforce.com/communit...4&postcount=54. It was very educational and recreational (and fun!)

Kent, I will second reading all of the stuff DanH has posted, his posts are really what got me going as well as a few PMs to him. I also had some fiberglass experience but it's been a long time. The best method I have found is to sandwich the plies between two sheets of plastic and wet them out (a lot easier if you put epoxy below and above the plies). Peel one side off, start putting on your part/plane and peel the other side off as you go. Then get air bubbles out, make it how you want and put peel ply on when you are done. Drop me a call Kent when you get to doing your fiberglass and I'll explain it better.