# Surface duplication on joining surfaces

**URL:** <https://discourse.mcneel.com/t/surface-duplication-on-joining-surfaces/181569>\
**Category:** Rhino for Mac\
**Tags:** mac\
**Created:** [May 7, 2024, 7:55am UTC](https://discourse.mcneel.com/t/surface-duplication-on-joining-surfaces/181569 "2024-05-07T07:55:27Z")\
**Posts on this page:** 7\
**Page:** 1

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**Author:** ![Neomega-Resin](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/neomega-resin/32/759868_2.png) [@Neomega-Resin](https://discourse.mcneel.com/u/Neomega-Resin)\
**Post date:** [May 7, 2024, 7:55am UTC](https://discourse.mcneel.com/t/surface-duplication-on-joining-surfaces/181569/1 "2024-05-07T07:55:27Z")

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Hi. An issue has suddenly turned up I’m trying to join surfaces, the surfaced say they are joined but it also then duplicated the surface for some reason. It also then created a large number of surface edges etc, some which then become undeletable. I opened a new page, made 2 surfaces and the same happened. What have I ticked, or missed?

Rhino 7 on a Macbook PRO

Any ideas please?

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**Author:** ![Helvetosaur](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/helvetosaur/32/635974_2.png) [@Helvetosaur](https://discourse.mcneel.com/u/Helvetosaur)\
**Post date:** [May 7, 2024, 8:03am UTC](https://discourse.mcneel.com/t/surface-duplication-on-joining-surfaces/181569/2 "2024-05-07T08:03:23Z")

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Can you post a file in the “before joining” condition with instructions on how to reproduce?

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**Author:** ![Neomega-Resin](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/neomega-resin/32/759868_2.png) [@Neomega-Resin](https://discourse.mcneel.com/u/Neomega-Resin)\
**Post date:** [May 7, 2024, 11:34am UTC](https://discourse.mcneel.com/t/surface-duplication-on-joining-surfaces/181569/3 "2024-05-07T11:34:46Z")

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OK, 2.9 is prior to joining attempt, 2.01 is after joining. Loads of surfaces happening now.

[albatross seat2.0.3dm](https://discourse.mcneel.com/uploads/short-url/r2EDUPCXhhrr47GFWnrrul6Z1VV.3dm) (3.7 MB)  
[albatross seat2.01.3dm](https://discourse.mcneel.com/uploads/short-url/4kfxwkhZ5jxQlp3wjkccKDBKcLz.3dm) (1.1 MB)

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<div class="post-metadata">

**Author:** ![Helvetosaur](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/helvetosaur/32/635974_2.png) [@Helvetosaur](https://discourse.mcneel.com/u/Helvetosaur)\
**Post date:** [May 7, 2024, 12:55pm UTC](https://discourse.mcneel.com/t/surface-duplication-on-joining-surfaces/181569/4 "2024-05-07T12:55:02Z")

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I don’t see a 2.9, I see a 2.01 and a 2.03… Both files look the same to me though.

SelAll shows `2 text dots, 42 curves, 42 surfaces, 8 polysurfaces added to selection.`

SelDup shows `Found 36 duplicates. 5 curves, 31 surfaces added to selection.`

So there are 31 duplicated surfaces in there… Don’t know if that is before or after.

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<div class="post-metadata">

**Author:** ![Neomega-Resin](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/neomega-resin/32/759868_2.png) [@Neomega-Resin](https://discourse.mcneel.com/u/Neomega-Resin)\
**Post date:** [May 7, 2024, 1:06pm UTC](https://discourse.mcneel.com/t/surface-duplication-on-joining-surfaces/181569/5 "2024-05-07T13:06:01Z")

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Sorry, It should read 2.0 not 2.9 🙄

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<div class="post-metadata">

**Author:** ![Neomega-Resin](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/neomega-resin/32/759868_2.png) [@Neomega-Resin](https://discourse.mcneel.com/u/Neomega-Resin)\
**Post date:** [May 7, 2024, 1:12pm UTC](https://discourse.mcneel.com/t/surface-duplication-on-joining-surfaces/181569/6 "2024-05-07T13:12:03Z")

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OK, Maybe this helps?  
[albatross seat prejoin.3dm](https://discourse.mcneel.com/uploads/short-url/rQLMeBrpA8VvmMvxaZU82ym7Ra6.3dm) (152.3 KB)  
[albatross seat afterjoin.3dm](https://discourse.mcneel.com/uploads/short-url/jnPcFdB06ytAIbX8Mqr8fnHHy8n.3dm) (181.0 KB)

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<div class="post-metadata">

**Author:** ![Neomega-Resin](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/neomega-resin/32/759868_2.png) [@Neomega-Resin](https://discourse.mcneel.com/u/Neomega-Resin)\
**Post date:** [May 7, 2024, 1:43pm UTC](https://discourse.mcneel.com/t/surface-duplication-on-joining-surfaces/181569/7 "2024-05-07T13:43:57Z")

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In the end, I closed it all down. On reopening, it seems to be behaving for now! 🤞

Thanks!

G