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national 200 Front section replacement

Posted: Wed. Oct. 25, 2017 3:20 pm
by Dinger240
Does anyone have any experience changing a front section. I found another one in great shape.Not sure how to do it. Thanks

Re: national 200 Front section replacement

Posted: Wed. Oct. 25, 2017 5:16 pm
by franco b
The older boilers have the sections connected by push nipples which are tapered smooth bushings. Undo any tie rods and then tap in something wedge shaped like a cold chisel close to the nipples, a little bit to each in turn. The location of the nipples are easily seen by the rounded portions of the casting. Usually one at each lower corner and possibly one big one on top.

Assembly is the opposite by gradually drawing together with the tie rods. Once drawn together loosen the tie rods to allow for expansion. Some have a soft washer to absorb expansion.

Re: national 200 Front section replacement

Posted: Thu. Oct. 26, 2017 3:41 pm
by Pacowy
fb,

Whistlenut once advised me to use hard plastic as the wedge, to minimize the possibility of having bad things happen.

Some of the old sectional boilers, like HB Smith, connected the sections to the header and mudlegs, but not to each other, so they had no push nipples. The Nationals I've seen were set up as you say, but I haven't been able to find a pic of a 200 to confirm.

Mike

Re: national 200 Front section replacement

Posted: Thu. Oct. 26, 2017 3:55 pm
by franco b
Pacowy wrote:
Thu. Oct. 26, 2017 3:41 pm
fb,

Whistlenut once advised me to use hard plastic as the wedge, to minimize the possibility of having bad things happen.

Some of the old sectional boilers, like HB Smith, connected the sections to the header and mudlegs, but not to each other, so they had no push nipples. The Nationals I've seen were set up as you say, but I haven't been able to find a pic of a 200 to confirm.

Mike
Yes, my experience is from over 50 years ago, and things become hazy.

I would think the plastic wedges used in tree work would be good.

Thanks for jumping in with more recent experience.

Re: national 200 Front section replacement

Posted: Thu. Oct. 26, 2017 4:00 pm
by Pacowy
You're welcome, and yes he specifically recommended the tree ones.

Mike

Re: national 200 Front section replacement

Posted: Tue. Nov. 21, 2017 7:00 pm
by Dinger240
Should I use any type of sealant when I put it back together ?