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Airguns by Make and Model => Diana Airguns => Topic started by: hzyl0402 on November 02, 2011, 01:19:07 PM

Title: Rebuild my 48, questions!
Post by: hzyl0402 on November 02, 2011, 01:19:07 PM
All right guys,

Just checked the tracking info, JM's lube combo and new seal will come today, and I am going to dissemble my RWS 48 again tonight. Here are some of questions by far in my mind, and I think more will be coming when I am doing the job.
1. I have a bottle of isopropyl alcohol, 70% by volume for first aid, can I use it for cleaning?
2. Is kitchen towel OK for internal part wiping?
3. As told by Dustin in my previous topic " The moly for the outside of the seal , clear tar for outside of compression tube and heavy tar for the spring." I want to know how much should I use them?

Anything you might think a newbie should know, please feel free to point out!

Thank you all!

Liang
Title: Re: Rebuild my 48, questions!
Post by: Mark 611 on November 02, 2011, 01:32:16 PM
I know my friends will have differing opinions of how I do things so you need to take in all the info you can here here's how I do it, I know some guys burnish lube {Molly or other} into the compression tube I don't because I don't want any dieseling or any detonation issues! so I don't use any lube in the tube accept on the back side of the piston seal and only a very thin coating that you can see thru just a light film! and then I rub Molly about an inch behind the seal and at the other end of the piston here again very thin! I use Molly on all my moving parts outside of the compression area here again alittle gos along way! I'll stop here and let some one else put their 2ct in and if you need to talk to me about this I'll give you PH#  :P
Title: Re: Rebuild my 48, questions!
Post by: Kailua on November 02, 2011, 01:48:55 PM
ARH also sells piston buttons.  Could use an expert tuners opinion on this also.  Also a 1/2" wooden dowel and cut a slit down the middle where you can attach a rag to clean the cylinder.
Title: Re: Rebuild my 48, questions!
Post by: Mark 611 on November 02, 2011, 01:58:00 PM
Usually when I do a tune I'll polish the piston and clean it with brake cleaner or other like starting fluid because it will dry up any oils left behind or buffing compound! if you want to button a piston clean it as said place the buttons every 120 degrees around the piston than then you'll have to sand them to fit the compression tube. :P
Title: Re: Rebuild my 48, questions!
Post by: Gary on November 02, 2011, 01:59:24 PM
The alcohol you have will work.
I use the moly on the compression tube very sparingly and then wipe out with a clean paper towel. Also behind the seal and at the rear of the piston ad on other moving parts such as cocking lever pins etc.
Clear tar on the outside of the compression tube.
Heavy tar on the spring. Do not glob it on. I try to make my spring look like it has been painted. Use to much and the rifle will shoot real slow.
Gary
PS: A little moly on the guide and spring ends. Just remember a little goes a long way.
Title: Re: Rebuild my 48, questions!
Post by: hzyl0402 on November 02, 2011, 02:11:23 PM
Thanks guys, just check the mail box, and here they are! I can't wait no longer, let do it!
let me dissemble my gun, and I will let you know what's going on.
Title: Re: Rebuild my 48, questions!
Post by: hzyl0402 on November 02, 2011, 02:33:28 PM
Now every thing is out. looks like I used too many heavy tar last time....
Next step, Alcohol + kitchen towel!
Title: Re: Rebuild my 48, questions!
Post by: hzyl0402 on November 02, 2011, 02:40:07 PM
Here is JM's spring, look at the tar, is it still too thick? should I clean it up and recoat with lighter heavy tar?
Title: Re: Rebuild my 48, questions!
Post by: Gary on November 02, 2011, 02:43:51 PM
A lot of tar on that spring, I would clean it off and try again.
Gary
Title: Re: Rebuild my 48, questions!
Post by: Mark 611 on November 02, 2011, 03:00:03 PM
yes sir thats allot! :P
Title: Re: Rebuild my 48, questions!
Post by: hzyl0402 on November 02, 2011, 03:51:36 PM
How about now? is it too light? and should I lube the rear spring guide? and how? ::)

Liang
Title: Re: Rebuild my 48, questions!
Post by: JimL911 on November 02, 2011, 03:59:06 PM
I use a little more tar. I run light strings down the length of spring at 12,3,6 and 9 o'clock. Normal use will spread it.
Title: Re: Rebuild my 48, questions!
Post by: Mark 611 on November 02, 2011, 03:59:58 PM
ya that's a tic to light, rub enough on the out side of the spring to lightly cover it I try to string it like a spied er web! and use a light coat of molly on the tips of the spring ends and spring guide needs a light coat of molly as well :P
Title: Re: Rebuild my 48, questions!
Post by: hzyl0402 on November 02, 2011, 05:08:45 PM
seal problem solved.
here is the piston, seal coated with light moly and end of the piston with light moly. is there anything I should do before put it into compression chamber?
Title: Re: Rebuild my 48, questions!
Post by: Mark 611 on November 02, 2011, 06:34:09 PM
 nope! :P
Title: Re: Rebuild my 48, questions!
Post by: hzyl0402 on November 02, 2011, 06:36:49 PM
Finally!!! I finished!!! This thing is sweet! the machinery has no noisy at all! Like the clear tar very much, just a little can make the gun super smooth.

Thanks again everyone!

Liang
Title: Re: Rebuild my 48, questions!
Post by: Mark 611 on November 02, 2011, 06:48:07 PM
Glad we could help! :P
Title: Re: Rebuild my 48, questions!
Post by: ray in wi on November 02, 2011, 09:00:27 PM
Wow! That was awesome the  way you guys helped out on this tune!!! This is great place to visit!!
About the only other thing I would have suggested  is to take a fine  to medium file and take all the burrs off the tube, piston and cocking shoe, but hey, you can do it next time.
Ray
Title: Re: Rebuild my 48, questions!
Post by: Mark 611 on November 02, 2011, 09:09:09 PM
ray they don't have a cocking shoe or a slot to worry about like a break barrel! :P
Title: Re: Rebuild my 48, questions!
Post by: s10gto on November 02, 2011, 11:14:24 PM
Nice Job Liang!  ;D Enjoy

Title: Re: Rebuild my 48, questions!
Post by: hzyl0402 on November 03, 2011, 05:34:43 PM
Hey guys,

Thanks again. And last night, I tested my gun, and I found out it's loader than before tuning. is it because I reduced the amount of heavy tar on the spring?

Liang
Title: Re: Rebuild my 48, questions!
Post by: Mark 611 on November 03, 2011, 07:05:46 PM
muzzle loud? :P
Title: Re: Rebuild my 48, questions!
Post by: s10gto on November 03, 2011, 07:29:12 PM
If muzzle loud very possible. By reducing the tar the FPS will go up.
Title: Re: Rebuild my 48, questions!
Post by: Jaymo on November 03, 2011, 07:55:19 PM
If you can ever afford a JM tune kit for your 48, it's a good one. I put one in my B30 a couple years ago. It went from a rough, gritty shooter to a smooth shooter with just a JM tune kit, JM seals, and the proper honing/polishing.
I've been using dry moly spray on the front/rear of the piston.
Title: Re: Rebuild my 48, questions!
Post by: s10gto on November 03, 2011, 08:23:06 PM
Got a JM VRT tune kit in my 52. Very smooth and puts out 18 FPE.
Title: Re: Rebuild my 48, questions!
Post by: hzyl0402 on November 03, 2011, 10:02:09 PM
The spring and seal in my 48 are all from JM, and it's the new ZRT kit. As you can see from the picture, I have barrel shroud. Before tuning it's as load as my Daisy 953, which is a single pump target rifle, shoots around 400fps with JSB 8.4g. But now, it's much loader. I think the barrel shroud will cover most of the air blast, maybe the extra noise is from the piston hits end of the compression chamber?

Liang
Title: Re: Rebuild my 48, questions!
Post by: s10gto on November 03, 2011, 10:27:48 PM
What weight pellets are you using? My 52 has the VRT kit and in .177 with 10.3 grain shoots high 800's for 17.5 to 18 FPE. The ZRT kit is a higher power kit. With a pellet too light it will be loud. Can sound like a rimfire .22LR. The piston can also hit if the pellet is too light. 
Title: Re: Rebuild my 48, questions!
Post by: hzyl0402 on November 03, 2011, 10:31:43 PM
What weight pellets are you using? My 52 has the VRT kit and in .177 with 10.3 grain shoots high 800's for 17.5 to 18 FPE. The ZRT kit is a higher power kit. With a pellet too light it will be loud. Can sound like a rimfire .22LR. The piston can also hit if the pellet is too light. 

I only use JSB heavy 10.2g. Of course it's quieter than the factory version, but it's loader than before tuning.

Liang
Title: Re: Rebuild my 48, questions!
Post by: s10gto on November 03, 2011, 10:36:14 PM
That should be just fine for pellets. With the ZRT kit it is probably close to 19 FPE and is normal. 
Title: Re: Rebuild my 48, questions!
Post by: hzyl0402 on November 04, 2011, 03:14:45 AM
By listen very carefully, I can tell the firing sound combines a solid hit sound, a sharp hit sound "ding" like 2 metals hit each other and last a low and solid "bu" from muzzle. Obviously the sharp hit sound "ding" the extra one and makes my gun loader. Is it because of the new seal I dropped in this time? Maybe it need more rounds to break in? Any one get any idea about that? Any previous experience on new seal?

Liang
Title: Re: Rebuild my 48, questions!
Post by: s10gto on November 04, 2011, 08:08:55 AM
Does sound a little strange. As far as JM's seals I have never had a single problem with them. I have had many. Only thing I can think of is check the Allen screw in the end of the compression tube that holds the cocking rod lug. I have had that loosen up. Maybe you are hearing it move upon firing. It would also not hold the breech seal tight to the barrel. After it is tight your cocking lever should be 2 1/4 inches from the receiver before it locks shut.

 
Title: Re: Rebuild my 48, questions!
Post by: s10gto on November 04, 2011, 08:10:23 AM

This may help too.  ;D

http://www.google.com/url?sa=t&rct=j&q=rws%2048%20tunning&source=web&cd=1&ved=0CCEQFjAA&url=http%3A%2F%2Fhome.comcast.net%2F~scot_for_sale%2Fguns%2FRWS48_tune%2Findex.html&ei=ecezTo6mOcOq0AGjspCdBA&usg=AFQjCNHEqrgqLj_uOU6tUIE53bXmwlVQIQ (http://www.google.com/url?sa=t&rct=j&q=rws%2048%20tunning&source=web&cd=1&ved=0CCEQFjAA&url=http%3A%2F%2Fhome.comcast.net%2F~scot_for_sale%2Fguns%2FRWS48_tune%2Findex.html&ei=ecezTo6mOcOq0AGjspCdBA&usg=AFQjCNHEqrgqLj_uOU6tUIE53bXmwlVQIQ)
Title: Re: Rebuild my 48, questions!
Post by: Mark 611 on November 04, 2011, 10:22:28 AM
Did the seal fit kinda snuggly in the compression tube when you put it in? If not your probably getting some piston slam also how'd the spring fit on the guide was it tight? :P
Title: Re: Rebuild my 48, questions!
Post by: Bullit on November 04, 2011, 05:13:47 PM
That's also what I'm thinking by your description of the sound... Piston Slam.
Liang, you also have posted that you had damaged a Leapers UTG scope with this air rifle.  Piston Slam will kill any scope.
Title: Re: Rebuild my 48, questions!
Post by: hzyl0402 on November 04, 2011, 05:59:15 PM
That's also what I'm thinking by your description of the sound... Piston Slam.
Liang, you also have posted that you had damaged a Leapers UTG scope with this air rifle.  Piston Slam will kill any scope.

That sound just come out from Wednesday after tuning, during the tuning the only part I changed was JM's seal. When I install the piston, I feel nice and tight. And the viberation don't have any change. Maybe it's not the problem you guys worry about. But I am not sure.
Actually I am just back from range, I am happy with today's shooting. After the whole tuning kit break it, it may become more smooth.

Here is the groups at 25m.
Title: Re: Rebuild my 48, questions!
Post by: Bullit on November 04, 2011, 06:37:36 PM
Well Helles Bells Liang!  There's not a thing wrong with those groups at 25.  You made us worry too much!  Keep practicing! :)