OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Walk Behind Lawn Mower Frames Question On Scott Bonnar Cylinder Mowers Repairing cracks on early solid deck SB45 14"

Hi Guys,

I'd like to get some advice with regards to repairing some pretty serious cracks on a solid deck Scott Bonnar 45 14". As i've been playing with my own Scotties lately, my Dad has decided to bring his around for a freshen up also. I've literally only looked at this mower a couple of times over the last 15 or so years and it's normally under a cover and covered in grass clippings. He's always had a local mower shop service and sharpen the machine and he reckons they look after him so I've never got involved, until now....

Well I hardly know where to begin... I pulled the reel out first as it needed to go off for powder coat before a sharpen. It had so much contact with the bedknife that I could hardly rotate it by hand, even with the chains removed - which were way over tensioned. The driveshaft has a huge amount of play inside the clutch and there is next to no self propulsion. The old man was informed by the mower shop that they'd replaced the clutch cable and adjusted it as best as possible but there is a design fault with the mower and this is as good as it gets. They also said there was no warranty on the cable or their worksmanship for this issue! I'm so pissed of that he's been taken for a ride by their absolute incompetence.

To make matters worse, I found this after washing it down.



So I'm wondering is it worth trying to fix this or is it too far gone? I'd like to get it sorted as he loves the mower and when the time comes for him to hang up the catcher he'll be glad to hand it on to my son to continue using. My welding skills aren't up to this task so I'd need to get it done professionally. I'd really appreciate any opinions or advice.

Cheers, Michael

Hi Michael, have you seen this thread?
https://www.outdoorking-forum.com.au/forum/ubbthreads.php?ubb=showflat&Number=48230#Post48230

I don't recall seeing a seriously cracked single deck SB45 before. It wouldn't have been an easy result to achieve. My guess is that it was caused by long-term running with the engine side clutch-half loose, due to the captive cotter having failed.

As you will notice from the other thread, your father's mower has the advantage of having a bolted-on deck, so there are two fairly practical ways to go. The first is to dismantle the deck by grinding off the welds holding its individual parts together, then repair the separate parts by welding and dressing them, then reassemble the parts by welding them together. The second is to just make a new deck, by measuring the parts of the old one and reproducing them, then welding them together. The second is probably easier, and is certainly better.

I think quite a number of Outdoorking people, and especially Deejay, will be very interested in this repair - particularly so if you make a new deck and publish the dimensions of each part.

Hi Grumpy,

Thanks very much for your reply. Yes I saw that thread and that's what prompted me to ask. I've got 2 sold deck SB45's and looked at plenty more but I've never seen one cracked like this. That's why I wasn't sure if it was worth fixing or not.

I'm assuming from your reply that you think it's worth doing and I certainly prefer the idea of fabricating a new deck. I guess I'll have to start making some enquiries.

I'll leave the "Is it worth it?" discussion to Deejay, who is our resident expert on reel mowers. You may have gathered from that other thread that I greatly prefer the single deck SB45 to the later ones, but that is an engineer's viewpoint, not a collector's. Deejay is the man.

Hi to grumpy and rolla, well that is a turn up for the books...I have never seen a cracked solid deck SB 45 before and yes it is definitely worth repairing in my opinion.
Thanks grumpy for your excellent advice, having a repair schedule posted here would be fabulous for the archives and it would be great to see this old soldier brought back to original condition and handed down in Rolla's family.

In my opinion, SB's decision to replace the solid deck with the later twin rail design was a mistake....the solid deck is a superior design.

Thanks guys,

That's good enough for me, I'll definitely get it fixed up but we wont rush it. I'll loan him one of my 17's for now so that we can take our time to find someone that will do a suitable job for a decent price. I'll be sure to update the thread when we have some progress.

Cheers, Michael

Hello rolla16v
Do we have an update on this as yet?
Which avenue did you pursue?
Cheers
Steve

Hi Steve, I haven't done anything with the cracked deck at this stage. I was lucky enough to find another machine going cheap for parts with a good deck, so I've made one good mower out of the two. I still have the cracked deck sitting here but now that I don't have a need for it, it's probably not worth fixing.