Parts repair help

I recently acquired a 1980 Hobie 18 SE. I have to repair a few things before I take her out for a sail. The foot of the mast is pulled out where the rivets are use to holds it down the mast foot on the cross bar. Can the mast be thru bolted? It seems like a logical repair to me.

The center of the casting of hinged base plate on the mast is also broken out. I assume that the part absolutely has to be replaced. If I an wrong please correct me. Any recommendations of where I can purchase said part.

How do I post/attach pictures?
Thanks for the help.
KJ

You can post pictures by using the "Img" button just below the subject line when creating the post. It will give you img and /img each inside []. You will need to upload the image to a 3rd party hosting service and put the link to the image between the two img tags.

I am not sure if you could use a thru bolt to re-attach the mast base. It would depend on if the bolt could freely pass completely through without needing modification. I'm pretty sure that's a structural part, so I'd advise against modification. I looked at my base and it looks like you would have to modify the hinge portion to use a single bolt. You MAY be able to use 2 bolts though, putting the bolt head on the inside and the nut on the outside. I'd check to make sure it all fits well and that the hinge freely fits into the base before fully assembling.

I would go with your assumption about replacing the broken part. Both the mast base and the hinge support the mast. If either fails, the mast will likely come down. I'm a firm believer that any damage or breakage should be fixed or replaced in any case. You don't want to be stranded out on the water or to have a failure that will cause more damage that will need additional repairs. Or worse, having that failure cause injury.

West Coast Sailing sells both parts but are temporarily out of stock:
Mast Base: https://westcoastsailing.net/hobie-18-mastbase-casting/
Hinge: https://westcoastsailing.net/hobie-18-mastbase-hinge/
After a quick google search, that was the only place I could find that sells the base. The hinge however is sold at many places, but all I checked were out of stock. Maybe a used one on EBay if you want it ASAP? I didn't check...

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Standard Hobie 18

The part that is attached to the front crossbar is the mast “step.” Does your mast step have two rivets or four? The step design was changed somewhere around the early 80’s to add two extra rivets. If you have the old version, you should consider upgrading. It would be difficult to thru-bolt the step. You would need to disassemble the front crossbar to gain access for installing the nuts (unless your plan is to literally bolt through the entire crossbar which would probably not be recommended).

If the existing rivet holes have become oversized, another option is to go up one size rivet from 3/16” to 1/4” diameter. You can also put washers on the inside of the crossbar to support the rivets but again, this requires disassembling the crossbar.

The broken hinge definitely needs to be replaced. You cannot safely raise and lower the mast without a functioning hinge.

Edit: Sorry, I re-read your post. Sounds like you’re saying the mast “base” pulled out of the bottom of the mast. I would not thru-bolt it. I would re-rivet it to the mast which will be a cleaner approach. You can get a good heavy duty rivet gun from Harbor Freaight for about $20 which will pull stainless rivets. If the mast or mast base is damaged where the old rivet holes were located, you should be able to drill new holes nearby.

sm