The chemical term ‘oxyacetylene’ has 6 syllables: ox.y.a.cet.yl.ene. The primary stress is on the 4th syllable ‘.cet.’. A secondary stress may be placed on the 1st ‘ox.’ and a 3rd (tertiary) perhaps on the last ‘.line’. Pronounce the 1st ‘o’ as a short sound as in ‘pot’. The consonant ‘x’ is ‘ks’. The 1st syllable becomes /Zk/, a closed syllable. The ‘y’ in the 2nd syllable is semivowel and is pronounced the long ‘e’ sound /i/ as an open syllable /si/ (the /i/ as in ‘be’.) The ’a’ is reduced to a schwa sound /ə/. The ‘c’ is /s/ before ‘e’ and ‘e’ is pronounced with its short sound /e/. So ‘.cet.’ becomes /set/ (the ‘e’ as in ‘bed’), a closed syllable. Reduce the semivowel ‘y’ to a schwa. The last syllable may be considered as a magic-e syllable. The ‘e’ is silent and the ‘i’ is pronounced with its long sound /i+/. The whole word is thus uttered in isolation as /1Zk.si.ə0set.əl1i+n/. The ‘l’ in the 5th syllable may also be syllabic.
This represents only how I would say it. There’re of course variant pronunciations to this word. Other respondents might want to enlighten you on this. I see few did already.
You're undoubtedly right, Rewboss. But still I believe, since it is forum devoted to phonetics, that we should use the IPA to 'promote' it as the easiest and most universal way of teaching and transcribing pronunciation . And if somebody still doesn't understand, then we should provide him with instructions that preceded my post [I personally find them very useful and accurate. I'm sure that they helped the person who started the thread.]. But this is only my point of view. I don't have to be right. And nobody has to accept it.